No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Iron and Calcium Bioavailability of Fortified Foods and Dietary Supplements
Abstract
Bioavailability is a key consideration when developing strategies for preventing mineral deficiencies through improved dietary supply. Factors that affect the bioavailability of iron and calcium, forms used for fortification and supplementation, and methods used to assess bioavailability are described. Illustrations of the impact of introducing iron-fortified foods in developing and industrialized countries are given, and the alternative approach of supplementation with iron and calcium is discussed.
... There is a complex association between dietary intake and nutrient stores, and a dose-response relationship is complicated by several factors, including impaired gastrointestinal absorption [16,[18][19][20], medications [21], cooking methods [21][22][23][24], and genetics [17,25]. Not all foods are equally bioavailable, for example hem iron derived from animal sources is more bioavailable and less affected by dietary factors compared to non-hem iron derived from plant sources and fortified foods [26,27]. Similarly, folic acid and synthetic vitamin B 12 used in food fortification are more bioavailable and less affected by impaired age-related gastrointestinal absorption compared to naturally occurring food-folate and vitamin B 12 [21,28]. ...
... There are underlying limitations in assessment of iron biomarkers. Bioavailability may impact dietary iron status [26]. For example, it is estimated that >15% of hem iron is absorbed versus <5% of non-hem iron due to diet-related factors [27]. ...
... Men derived more iron from cereals, bread, and beef and veal whereas women had more iron from non-hem sources such as cereals, bread, and vegetables. Select cereals and bread have been fortified with iron; however, bioavailability may be reduced due to the presence of phytates and fiber [26,50]. Therefore, the higher intake of hem iron from beef and veal among men may explain why their iron stores were larger. ...
Advanced-age adults may be at risk of iron, folate, and vitamin B12 deficiency due to low food intake and poor absorption. This study aimed to investigate the intake and adequacy of iron, folate, and vitamin B12 and their relationship with respective biomarker status. Face-to-face interviews with 216 Māori and 362 non-Māori included a detailed dietary assessment using 2 × 24-h multiple pass recalls. Serum ferritin, serum iron, total iron binding capacity, transferrin saturation, red blood cell folate, serum folate, serum vitamin B12 and hemoglobin were available at baseline. Regression techniques were used to estimate the association between dietary intake and biomarkers. The Estimated Average Requirement (EAR) was met by most participants (>88%) for dietary iron and vitamin B12 (>74%) but less than half (>42%) for folate. Increased dietary folate intake was associated with increased red blood cell (RBC) folate for Māori (p = 0.001), non-Māori (p = 0.014) and serum folate for Māori (p < 0.001). Folate intake >215 µg/day was associated with reduced risk of deficiency in RBC folate for Māori (p = 0.001). Strategies are needed to optimize the intake and bioavailability of foods rich in folate. There were no significant associations between dietary iron and vitamin B12 intake and their respective biomarkers, serum iron and serum vitamin B12.
... Most widely consumed are multivitamin/multimineral preparations 9,11 with Ca and Mg either as main components 12 or as single mineral supplements. 9,11 Inorganic Ca compounds like CaO, Ca(OH) 2 , and CaCO 3 are approved for supplementation in the US 13 and the European Union. 13,14 These compounds are considered to be bioavailable and can contribute to meeting requirements in humans. ...
... 9,11 Inorganic Ca compounds like CaO, Ca(OH) 2 , and CaCO 3 are approved for supplementation in the US 13 and the European Union. 13,14 These compounds are considered to be bioavailable and can contribute to meeting requirements in humans. 15 Conventionally prepared multimineral supplements require a homogeneous and stable mixture of different ingredients before pressing tablets. ...
... However, in long-term studies, this effect is often less pronounced or absent (for a review see Lynch 53 ). Mineral interactions can be observed in conventional supplements 8,13 and are thus not specific for nanostructured compounds. ...
Iron deficiency affects approximately 2 billion people worldwide, especially young women and children. Food fortification with iron is a sustainable approach to alleviate iron deficiency but remains a challenge. Water-soluble compounds with high bioavailability (e.g. the "gold standard" FeSO 4)) usually cause unacceptable sensory changes in foods, while compounds that are less reactive in food matrices are often less bioavailable. Solubility (and therefore bioavailability) can be improved by increasing the specific surface area (SSA) of the compound, i.e. decreasing its particle size to the nm range. Here, iron oxide-based nanostructured compounds with Mg or Ca are made using scalable flame aerosol technology. Addition of either element increased iron solubility to a level comparable to iron phosphate. Furthermore, these additions lightened the powder color and sensory changes in fruit yoghurt were less prominent than for FeSO 4.
... In particular, consumers with intolerance or allergy to dairy (which accounts for 72% of U.S. Ca intake) may benefit from more food-based alternatives to Ca supplementation [7]. In countries where dairy intake is low and osteoporosis is more prevalent, approaches to Ca fortification must be economically sustainable [37], and utilization of CBP presents an option for fortification of non-staple foods. ...
... Collectively, these data indicated that at 10% and 20% CBP addition levels in breading mixes, CBP did not compromise the sensory quality of fried catfish strips. This result is encouraging for CBP utilization in the current food matrix, as successful Ca fortification should not cause changes to sensory properties of the final product [37]. However, the observed outcomes within fried fish breading are not necessarily generalizable to other product applications. ...
Catfish are the predominant U.S. aquacultural product. However, byproducts from filleting, including bones that are high in calcium, typically go to waste or are sold as a low-valued feed. This research evaluated the potential use of catfish bone powder (CBP; 21.07% calcium) as a food ingredient. Catfish fillet strips were dredged with a breading mix (CBPM) containing 0% (0CBPM), 10% (10CBPM), and 20% (20CBPM) CBP before frying. Consumers (N = 211) evaluated sensory liking (nine-point hedonic scale) and attribute intensity (JAR scale), emotions (check-all-that-apply), and purchase intent (PI, yes/no) of samples. Color and texture were measured instrumentally. CBP did not show any negative effects on liking scores, although crispiness was scored higher for 20CBPM (mean = 6.88) than 10CBPM (mean = 6.43). Positive emotions were most relevant to CBP-containing samples, with significantly higher rates of adventurous and understanding. Information about calcium fortification using CBP increased PI to 81.04% for the 10CBPM and 83.89% for the 20CBPM samples and showed a greater effect on Latin Americans/Hispanics than U.S. Americans. Consumers were not averse to the consumption of CBP which can contribute to sustainable nutrition through waste reduction. Successful calcium fortification of fried catfish dredged with 20% CBP did not compromise sensory liking and may be feasible in other products.
... Manufacturers are not legally required to list the total P content on the food label or the contribution to daily P requirements, despite increasing pressure for this to be mandatory [30]. Processed foods with significant amounts of added inorganic P include meat, dairy, and bakery products, as well as a growing number of drinks such as colas and some flavored drinks, bottled water, malted drinks and sterilized, ultra-heat treated, and thickened or powdered milks [31,32] (Table 4). In addition, inorganic phosphates are added to several medications, such as antacids and many anti-hypertensive medications, as an excipient that aids in dispersion of the active drug ingredient once ingested [33,34]; these can vary between manufacturers and across different formulations of the same medication. ...
... Thus, although some cereals and green leafy vegetables and fruit may be rich in Ca (and also low in phosphate), given the low bioavailability of Ca from these sources, children with CKD are unlikely to consume sufficient quantities in order to meet nutritional requirements. The efficiency of absorption is influenced by the oxalate and phytic acid content of the food, the amount consumed [32], vitamin D status [39], and the child's age. In patients with v i t a m i n D d ef i c i en c y, de f i n ed as a se r u m 2 5hydroxyvitamin D level less than 75 nmol/L [10], only 10-15% of dietary Ca and approximately 60% of dietary P is absorbed, while the efficacy of intestinal Ca and P absorption in vitamin D replete subjects increases to 30-40% and 80%, respectively [9,40]. ...
In children with chronic kidney disease (CKD), optimal control of bone and mineral homeostasis is essential, not only for the prevention of debilitating skeletal complications and achieving adequate growth but also for preventing vascular calcification and cardiovascular disease. Complications of mineral bone disease (MBD) are common and contribute to the high morbidity and mortality seen in children with CKD. Although several studies describe the prevalence of abnormal calcium, phosphate, parathyroid hormone, and vitamin D levels as well as associated clinical and radiological complications and their medical management, little is known about the dietary requirements and management of calcium (Ca) and phosphate (P) in children with CKD. The Pediatric Renal Nutrition Taskforce (PRNT) is an international team of pediatric renal dietitians and pediatric nephrologists, who develop clinical practice recommendations (CPRs) for the nutritional management of various aspects of renal disease management in children. We present CPRs for the dietary intake of Ca and P in children with CKD stages 2–5 and on dialysis (CKD2-5D), describing the common Ca- and P-containing foods, the assessment of dietary Ca and P intake, requirements for Ca and P in healthy children and necessary modifications for children with CKD2-5D, and dietary management of hypo- and hypercalcemia and hyperphosphatemia. The statements have been graded, and statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs based on the clinical judgment of the treating physician and dietitian. These CPRs will be regularly audited and updated by the PRNT.
... In countries where sufficient calcium is obtained from dietary sources, calcium fortification will most likely be targeted towards the at-risk population such as adolescents and post-menopausal women. Calcium status of the population can be improved by fortifying staple foods with calcium, for instance rice and rice products (Fairweather-Tait & Teucher, 2002). In addition to that snacks and beverages can also be fortified with calcium. ...
... Qualitative methods determine absorbability through supplements with the help of post prandial parathyroid hormone. Surrogate measures determine long term response of calcium bioavailability through tests like bone mineral density (Fairweather-Tait & Teucher, 2002). From nutritional aspect, bioavailability means the fraction of ingested component which is available for utilization in normal physiological functions and is determined by in vivo assays (Guerra et al., 2012). ...
Structured Abstract
Background
Since prehistoric times, eggs have been used as a food source by human beings. Eggs are not only a good source of nutrition, but their shells also have many nutritional and non-nutritional components. A huge amount of eggshell waste is generated globally, and these eggshells are rich source of minerals especially calcium.
Scope and approach
Calcium carbonate comprises more than 90% by weight of an eggshell. Current review highlights how to minimise eggshell waste by extracting and utilizing its calcium for food fortification and manufacturing calcium rich food sources. It also explains how calcium from eggshell can be extracted through techniques such as electric discharge assisted mechanical milling, high intensity pulsed electric field, pulsed electric field and high energy milling.
Key findings and conclusion
This review further focuses on the utilization of eggshell in food industries which ultimately would reduce the global burden of eggshell waste to some extent
... Moreover, other essential nutrients such as selenium, polyphenol antioxidants, and carotenoids may be involved (6,8,9). A better understanding of the effect of calcium and natural antioxidants on redox active metal ions such as iron may open up for safer fortification strategies, but will clearly depend on a more quantitative description of metal speciation in the complex and changing matrix of various foods during digestion, as well on an understanding of the effects of metal binding to natural antioxidants on their radical scavenging efficiency (10)(11)(12). Understanding the dynamic aspects of metal speciation throughout digestion is also required to allow for better utilization of minerals already present in food through optimized processing in order to optimize bioavailability of these essential nutrients (12). Even calcium, without direct redox activity, presents a challenge for optimizing mineral nutrition, although a better understanding of the physicochemical aspects of calcium speciation may lead to improvements (13). ...
... A better understanding of the effect of calcium and natural antioxidants on redox active metal ions such as iron may open up for safer fortification strategies, but will clearly depend on a more quantitative description of metal speciation in the complex and changing matrix of various foods during digestion, as well on an understanding of the effects of metal binding to natural antioxidants on their radical scavenging efficiency (10)(11)(12). Understanding the dynamic aspects of metal speciation throughout digestion is also required to allow for better utilization of minerals already present in food through optimized processing in order to optimize bioavailability of these essential nutrients (12). Even calcium, without direct redox activity, presents a challenge for optimizing mineral nutrition, although a better understanding of the physicochemical aspects of calcium speciation may lead to improvements (13). ...
Insufficient uptake of essential metals leads to serious malnutrition, which is a worldwide problem. Low bioavailability of iron and calcium may lead to anemia and osteoporosis, respectively, even in individuals with a high dietary intake. For iron, fractionation of meat proteins was studied in order to increase iron bioavailability from other meal components, and uptake of iron was found to increase with minimal risk of increasing oxidative damage. Calcium binding to peptides was found to prevent formation of insoluble calcium salts otherwise hampering absorption particularly in combination with calcium hydroxycarboxylates, entailing spontaneous supersaturation. Based on a review of results from different strategies available for increasing bioavailability, safe iron fortification is suggested to be supported by calcium, with modulation of iron as a prooxidant.
... Another systematic review (Cancelo-Hidalgo et al., 2013) found that micro-encapsulated iron salts such as ferrous sulfate and retarded-release iron preparations had the lowest incidence of adverse effects, while simple salts such as ferrous glycine sulfate, ferrous gluconate, uncoated ferrous sulfate and ferrous fumarate were less well tolerated. Therefore, adverse effects seem to depend on the forms of iron preparations ingested and are less likely to occur when iron is provided in chelated form (Fairweather-Tait & Teucher, 2002). ...
Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the tolerable upper intake level (UL) for iron. Systematic reviews were conducted to identify evidence regarding high iron intakes and risk of chronic diseases, adverse gastrointestinal effects and adverse effects of iron supplementation in infancy, young childhood and pregnancy. It is established that systemic iron overload leads to organ toxicity, but no UL could be established. The only indicator for which a dose–response could be established was black stools, which reflect the presence of large amounts of unabsorbed iron in the gut. This is a conservative endpoint among the chain of events that may lead to systemic iron overload but is not adverse per se. Based on interventions in which black stools did not occur at supplemental iron intakes of 20–25 mg/day (added to a background intake of 15 mg/day), a safe level of intake for iron of 40 mg/day for adults (including pregnant and lactating women) was established. Using allometric scaling (body weight0.75), this value was scaled down to children and adolescents and safe levels of intakes between 10 mg/day (1–3 years) and 35 mg/day (15–17 years) were derived. For infants 7–11 months of age who have a higher iron requirement than young children, allometric scaling was applied to the supplemental iron intakes (i.e. 25 mg/day) and resulted in a safe level of supplemental iron intake of 5 mg/day. This value was extended to 4–6 month‐old infants and refers to iron intakes from fortified foods and food supplements, not from infant and follow‐on formulae. The application of the safe level of intake is more limited than a UL because the intake level at which the risk of adverse effects starts to increase is not defined.
... Amongst the food products studied, several were either processed with the aid of Ca e.g., calcium sulphate and calcium chloride were used as firming agents in tofu and kidney beans, respectively, or fortified with tricalcium phosphate or mixtures (di and tri-calcium) in the case of the plant-based beverages (with the exception of the soy drink). It is generally accepted that Ca fortified foods contain highly bioavailable Ca in the same range as milk (Fairweather-Tait & Teucher, 2002;Fardet et al., 2019;Shkembi & Huppertz, 2021). White bread, tortillas, dairy products and tofu enriched/processed with the main Ca compounds used in fortification (calcium sulphate, carbonate, chloride and phosphates) have been found to have a bioavailability equivalent or higher than that of milk (Shkembi & Huppertz, 2021). ...
... Seven of the analyzed DSs were enriched with Fe fumarate or Fe gluconate (marked with * in Table S1). These organic compounds of Fe are the most popular forms of Fe in DSs [55], and they are highly bioavailable due to their easy ionization [56]. For Fe, the RDA for the Polish population is 10 mg/day for men [47]. ...
The study aimed to assess the health value and safety associated with the consumption of the chosen 37 beetroot-based dietary supplements (DSs). An optimized and validated analytical procedure, using a method called microwave plasma atomic emission spectrometry (MP-AES), was developed to determine the profiles of 19 elements (Na, K, Fe, Ca, Pt, Zn, Cd, Cu, V, Co, Ni, Pb, Mo, Mg, Al, Mn, Sr, Cr, Ba) in the DSs. The products were assessed for compliance with the recommended daily doses for the chosen elements, and any deviations were identified. Results showed that powders constituted a richer source of elements than capsules and tablets. The exception was iron-enriched products, which provided the highest dose of Fe (3.75 to 25 mg/daily dose). Safety assessment was evaluated in 3 steps, including (1) the determination of levels of Al, Ba, Cd, and Pb; (2) comparison of their content with the permissible contamination limits; and (3) comparison of the weekly or monthly intake of Al and Cd with the provisional tolerable weekly (PTWI) or monthly (PTMI) intake, respectively. The content of Ba was evaluated because of the oral reference dose (RfD). Five products were significantly contaminated with Cd (4–134% of PTMI Cd), two with Al (11–12%), and three with Ba (1.085–1.331 µg/d.d.). Lead was not detected above the LOQ (0.035 mg/kg). Factor analysis was employed to differentiate between the pharmaceutical forms (capsules, tablets, and powders) and determine the origin of the powder contained in the capsules. These results highlight the importance of implementing more stringent control measures and regulatory changes in the DSs market to ensure consumer safety.
... A higher intake of calcium from food or calcium supplements can increase bone mineral content and density while reducing the risk of fractures during menopause . Thus, calcium is necessary for bone accretion ( Zhu & Prince, 2012 ), and calcium bioavailability is an important factor influencing bone health ( Fairweather-Tait & Teucher, 2002 ). Nevertheless, besides intrinsic factors, such as genetic and metabolic characteristics ( Bueno & Czepielewski, 2008 ), extrinsic factors including dietary nutrition and pharmacological compounds may have an impact on intestinal calcium absorption ( Areco et al., 2015 ). ...
Probiotics and isoflavones have a promising therapeutic effect on calcium status and bone health, but there are only limited studies focusing on these products. The present study aimed to 1) determine the potential bioaccessibility of calcium from soybean products (raw soybean and tempeh) and a probiotic strain (Lactobacillus acidophilus) and to 2) evaluate whether the studied products and strain have an impact on the potential bioaccessibility of calcium from inorganic and organic calcium salts. The bioaccessibility of calcium was determined based on enzymatic in vitro digestion, and calcium content by flame atomic absorption spectrometry. The average potential calcium bioaccessibility from tempeh was 10% and from raw soybean was 2%, while probiotics could release over 85% of potential bioaccessible calcium during enzymatic digestion. In conclusion, the potential bioaccessibility of calcium from tempeh and soybeans is low. Soybean products decrease the bioaccessibility of calcium from organic and inorganic calcium salts, while probiotics could improve the bioavailability of calcium from these salts.
... Singh, in 2009, in his study, stated that micronutrients play an essential role in improving immunity, cognition, and brain development in children [34]. While several of the available pediatric ONS contain a variety of micronutrients, the absorption efficiency of these micronutrients is crucial for them to carry out vital functions [35]. ...
Introduction: Optimum nutrition is the cornerstone of child growth and development. Childhood is a period of rapid growth and development. Children of preschool age have higher nutritional needs and are often at risk of nutrient deficiencies. Objective: The present study was designed to evaluate the effect of an oral nutritional supplement (ONS) on growth parameters in a representative population. Methods: We used the systems-biology-based mathematical model for child growth to analyze the effect of ONS on growth in a representative in silico population of preschool children. The analysis included changes in average growth velocities of weight, height, muscle mass, fat mass, fat-free mass, and bone mass. We used meta-data analysis for evaluating the absorption of micronutrients present in the ONS that affects growth in preschool children. Results: The results of the analysis showed one serving of ONS in milk/day improved the weight gain velocity by 1.7 times in preschool children. The linear growth was 1.04 times higher than the control. The absorption of micronutrients such as iron, vitamin K, calcium, and magnesium was higher in the ONS group. Conclusions: This study indicates that the ONS containing macro and micronutrients, docosahexaenoic acid (DHA), and prebiotics can potentiate growth and development in preschool children. It provides micronutrients that can be readily absorbed which are essential for other vital functions in the body.
... When 200 mg of calcium is taken per day, absorption is approximately 45% but drops to 15% when taking more than 2000 mg per day. [13]. Additionally, age can have an impact on how well dietary calcium is absorbed. ...
Background:
Coronaviruses (COV) are a large family of viruses that cause infections ranging from the common cold to more serious diseases. Mild to severe respiratory illnesses have been linked to coronavirus disease 2019 (COVID-19), which has been classified as a pandemic disease by the World Health Organization. It has been demonstrated that the severity of COVID-19 is highly positively linked with hypocalcemia. Furthermore, calcium imbalances among other electrolytes are linked to the prognosis of COVID-19.
Objectives:
This study demonstrates a connection between serum calcium levels and COVID-19 as biomedical indicators of COVID-19 infections in Sulaymaniyah city, Iraq.
Methods:
A cross-sectional study was conducted at Baxshin Hospital for about two months from February 2022 to April 2022. The work was conducted with a total of 40 patients including 22 males and 18 females. The patients' ages ranged from 22 to 80 years old. By analyzing a sample from a nasopharyngeal swab and performing real-time reverse transcription-polymerase chain reaction (RT-PCR), all of the patients tested positive as having COVID-19 infection. Serum calcium was determined from the blood samples of the patients in order to evaluate their serum calcium levels. The statistical package for social science (SPSS) was utilized to examine the obtained data.
Results:
The study revealed a level of calcium between 6.10 and 9.86 mg/dL in male and female patients. The majority of the female patients (61%) displayed low levels of serum calcium, and 33% of the males had a low level of calcium. It can be seen that the highest rate of male patients (66.6%) exhibited a normal level of serum calcium, while 33.3% showed decreased serum calcium. Based on gender and age groups, a statistically significant difference in calcium levels was observed.
Conclusions:
This study discovered that infection with COVID-19 has some significant laboratory abnormalities, including hypocalcemia, showing that serum calcium might be employed as a prognostic marker in the clinic.
... A common remedy to iron malnutrition is through iron supplementation. For this purpose, different sources have been used, such as elemental iron and some common iron salts, such as iron fumarate, citrate, carbonate, and sulphate [7]. Nevertheless, these have shortcomings, including the lack of iron bioavailability [8,9], which can cause health issues such as gastrointestinal irritation, vomiting, lethargy, pneumonitis or convulsions [10], and can alter food properties [11]. ...
Given the importance of iron in human nutrition and the significance of waste and by-product valorisation in a circular economy environment, we investigated the effects of protein and iron concentration on the production yield of iron–peptide complexes from spent Saccharomyces cerevisiae. For this purpose, different amounts of protein and iron were used in the complexation process. The results have shown that higher concentrations, although permitting a faster and larger scale process, provide a significantly lower complexation yield, which deems the process less feasible. This is corroborated by fluorescence analysis, which shows a lower degree of complexation with higher protein concentration. In addition, varying the concentration of iron does not change the quality of formed complexes, as evidenced by Fourier transform infrared spectroscopy (FT-IR) analysis. The morphology of all samples was also evaluated using scanning electron microscopy (SEM). Therefore, further studies are needed to optimize the process and to evaluate the best conditions for an economically sound valorization process for iron–peptide complexes. Nonetheless, current results in the development of a new process for the valorisation of spent yeast, in the form of iron-peptide complexes, look promising.
... Calcium lactate is an organic salt of calcium with a relatively high bioavailability and good solubility [15]. Calcium lactate is a component often used in supplements recommended for menopausal women [16,17]. An effective and easy way to increase the amount of calcium in the diet is through functional foods that contain much more calcium than natural foods [18]. ...
This study aimed to evaluate the effects of enriched pumpkin on calcium status in ovariectomized rats. The study was conducted in sixty female Wistar rats, which were divided into six groups: a group fed a standard diet (C) and five ovariectomized groups fed a standard diet (OVX_C) or a diet with calcium lactate (CaL), with calcium lactate-enriched pumpkin (P_CaL), with calcium lactate and alendronate (CaL_B), or with calcium lactate-enriched pumpkin with alendronate (P_CaL_B). After 12 weeks of the intervention, the rats were sacrificed, and their blood and tissues were collected. The calcium concentrations in serum and in tissues were measured using flame atomic absorption spectrometry (AAS). Serum concentrations of procollagen type-1 amino-terminal propeptide (PINP), parathyroid hormone PTH, estrogen (ES), and osteocalcin (OC) were determined with enzyme-linked immunosorbent assay (ELISA). It was found that enriched pumpkin increased the calcium level in the kidneys (194.13 ± 41.01 mg) compared to the C (87.88 ± 12.42 mg) and OVX_C (79.29 ± 7.66 mg) groups. The addition of alendronate increased the calcium level in the femurs (267.63 ± 23.63 mg) and more than six times in the kidneys (541.33 ± 62.91 mg) compared to the OVX_C group (234.53 ± 21.67 mg and 87.88 ± 12.42 mg, respectively). We found that the CaL, P_CaL, and CaL_B groups had significantly lower PINP serum concentrations (4.45 ± 0.82 ng/mL, 4.14 ± 0.69 ng/mL, and 3.77 ± 0.33 ng/mL) and higher PTH serum levels (3.39 ± 0.54 ng/dL, 3.38 ± 0.57 ng/dL, and 3.47 ± 0.28 ng/dL) than the OVX_C group (4.69 ± 0.82 ng/mL and 2.59 ± 0.45 ng/dL, respectively). In conclusion, pumpkin enriched with calcium lactate affects calcium status and normalizes PINP and PTH serum levels in ovariectomized rats. Diet with enriched pumpkin and alendronate increase calcium concentration in the femur. Enriched pumpkin causes calcium to accumulate in the kidneys of ovariectomized rats; alendronate significantly exacerbates this effect.
... The best iron source was the product 6HeB. All the analysed iron-enriched products contained organic salt of Fe-iron gluconate which is one of the most common Fe compounds used in dietary supplements [49]. Dietary iron comes in two forms: haem available in animal products (red meat, offal, liver) and non-haem present in plant-based products. ...
There is a lack of data on the actual composition and effectiveness of beetroot-based dietary supplements. The research aimed to determine the profile of 22 elements (Na, K, Ca, Mg, P, Fe, As, Se, Zn, Cu, Ag, Co, Ni, Mo, Al, Mn, Sr, Cr, Ba, Li, Pb, Cd) in beetroot and its supplements by the microwave plasma atomic emission spectrometry (MP-AES) method. The analytical procedure was optimised and validated. The composition of both groups was compared, assessing compliance with the recommended daily doses for the chosen elements, and the health risk was estimated. Furthermore, chemometric analysis was applied. Beetroots constituted a significant source of elements, especially K, Na, Mg, Ca, P, in contrast to supplements which contained their negligible amounts except from iron-enriched products which provided notable amounts of Fe (38.3–88% of the Recommended Dietary Allowance for an adult male from 19 to 75 years old). Some products were significantly contaminated with toxic elements (As, Cd). Factor and cluster analyses were helpful in the differentiation of beetroot and its supplements in view of their type (vegetable, supplement, iron-enriched supplement), origin, type of cultivation (conventional, organic), and form (capsule, tablet) based on their mineral composition. The obtained results indicate the need for more stringent control of supplements, as they may pose a significant health risk to consumers.
... Ca absorption varies inversely with dietary Ca intake. Absorption of Ca from food is about 45% at intakes of 200 mg/day, but only 15% when intakes are higher than 2,000 mg/day (Fairweather-Tait & Teucher, 2002). Fractional absorption gradually declines with age (Heaney et al., 1989). ...
We report the trace element status of residents living in areas with naturally sulphide-rich bedrock and soil in two municipalities in Finland, Sotkamo and Kaavi. Altogether, 225 people from these sparsely populated regions participated voluntarily by providing hair and blood samples. The concentrations of calcium, zinc and copper in serum as well as selenium and cadmium in whole blood did not show correlation with those concentrations in hair samples. Calcium concentration in serum was slightly lower in the sulphide-rich areas (median value 91.4 mg/l, n = 103) than in the areas with adjacent sulphur-poor bedrock (median value 93.6 mg/l, n = 82). The concentrations of Ni and Mn in hair correlated with those in drinking water. The highest Mn and Ni concentrations in the water samples from private wells were 1620 µg/l and 51 µg/l and the highest concentrations in human hair samples 36.44 mg/kg and 12.3 mg/kg, respectively. The challenge with elevated trace element concentrations in some well waters is well documented. In northern countries (Finland, Sweden, Norway and Canada), only 10% of the population depend on private well water, and 90% have access to monitored municipal water supplies. Compared with data available from sulphide mine sites globally, the nickel and manganese concentrations in human hair samples were high in our sulphide-rich study area at Sotkamo representing the trace element status of residents under natural conditions.
... Ca absorption varies inversely with dietary Ca intake. Absorption of Ca from food is about 45% at intakes of 200 mg/day, but only 15% when intakes are higher than 2,000 mg/day (Fairweather-Tait & Teucher, 2002). Fractional absorption gradually declines with age (Heaney et al., 1989). ...
We report the trace element status of residents living in areas with naturally sulphide-rich bedrock and soil in two municipalities in Finland, Sotkamo and Kaavi. Altogether, 225 people from these sparsely populated regions participated voluntarily by providing hair and blood samples. The concentrations of calcium, zinc and copper in serum as well as selenium and cadmium in whole blood did not show correlation with those concentrations in hair samples. Calcium concentration in serum was slightly lower in the sulphide-rich areas (median value 91.4 mg/l, n = 103) than in the areas with adjacent sulphur-poor bedrock (median value 93.6 mg/l, n = 82). The concentrations of Ni and Mn in hair correlated with those in drinking water. The highest Mn and Ni concentrations in the water samples from private wells were 1620 lg/l and 51 lg/l and the highest concentrations in human hair samples 36.44 mg/kg and 12.3 mg/kg, respectively. The challenge with elevated trace element concentrations in some well waters is well documented. In northern countries (Finland, Sweden, Norway and Canada), only 10% of the population depend on private well water, and 90% have access to monitored municipal water supplies. Compared with data available from sulphide mine sites globally, the nickel and manganese concentrations in human hair samples were high in our sulphide-rich study area at Sotkamo representing the trace element status of residents under natural conditions.
... These deficiencies are often compensated by using fortification, enriching foods with micronutrients during processing (Garrett et al., 2019). Different means and methods of food fortification are used combining suitable food vehicles with the best mineral source in the means of solubility, bioavailability, absorption and price to reach the targeted population (Fairweather-Tait & Teucher, 2002). ...
Food fortification has been used for many years to combat micronutrient deficiencies; the main challenge with food fortification is the combination of a bioavailable, affordable fortificant with the best (food) vehicle as a carrier to reach at-risk populations. This paper considers mineral deficiencies, especially iron, food fortification, target populations, and the use of chelates in food fortification, as well as different types of mineral-chelate complexes, advantages and limitations of previous trials, methods used for analysis of these complexes, bioavailability of minerals, factors influencing it, and methods particularly those in vitro for predicting outcomes. Three innovative methods (encapsulation, nanoparticulation, and chelation) were explored, which aim to overcome problems associated with conventional fortification, especially those affecting organoleptic properties and bioavailability; but often lead to the emergence of new limitations (for example instability, impracticality and high costs) requiring further research.
... Although the three supplements contain Si in the same chemical form, that is, orthosilicic acid, the presentation form (liquid versus powder) and the rest of the ingredients of the formulation could affect Si bioavailability. In this sense, the presence of other nutrients or ingredients together with a mineral, in a supplement or in the diet, could improve or diminish its bioavailability, since they can interact through binding or competitive interaction 18 . Moreover, since it is known that solubility affects Si absorption 19 , our results may suggest that the powder product (Orgono Powder) presents similar solubility, once dissolved in water, to the liquid formulations, and this results in a similar relative absorption. ...
The purpose of the present study was to compare the relative absorption of a new powder presentation of silicon (Si) as orthosilicic acid with maltodextrin (Orgono Powder) compared to usual Si liquid presentations as orthosilicic acid with Equisetum arvense and Rosmarinus officinalis (G5 Siliplant) and orthosilicic acid with aloe vera (G7 Aloe). All dietary supplements were administered at the same Si oral dose (21.6 mg) in a randomized, double-blind, crossover post-prandial study conducted in 5 healthy men. Urine was collected at baseline and over the 6-h post-dose period in 2 separate 3-h collections for the analysis of Si concentration, which was conducted by inductively coupled plasma optical emission spectrometry as the gold standard method. No significant differences in total urinary Si excretion were found after the intake of these 3 dietary supplements; 34.6%, 32.4% and 27.2% of the ingested Si from G7 Aloe, G5 Siliplant and Orgono Powder, respectively, was excreted in urine over the 6-h follow-up period. The 3 different oral Si formulations tested, in powder and liquid presentations, provide highly bioavailable Si and present an equivalent relative absorption in healthy humans.
... Supplementation with various calcium preparations is the most widely used approach to increase calcium intake. 39 There are a number of commercially available calcium supplements which vary in calcium content and bioavailability. CaP-HMP in this study had a calcium content that ranged from 60.93 to 97.65 mg g -1 , which was very close to that of calcium gluconate (90 mg g -1 ) and calcium lactate (130 mg g -1 ). ...
BACKGROUND
Calcium pectinate (CaP) gel is traditionally prepared by de‐esterifying high methoxyl pectin (HMP) to low methoxyl pectin (LMP), followed by gelation with calcium. To save both time and cost in the production of CaP gel, an alternative method was developed by the addition of CaCl2 to HMP at alkaline pH. To optimize the production, response surface methodology (RSM) was used to investigate the effects of temperature (30–50 °C), time (20–40 min) and pH (8–10) on yield, calcium content of the CaP gel and the degree of esterification (DE) of pectin following decalcification of CaP (DC‐pectin).
RESULTS
The linear term for pH had a significant effect (P < 0.01) on all three responses, whereas interaction effects were not significant (P > 0.01), except on the calcium content (P < 0.01). The optimized process conditions (temperature, time and pH) to obtain maximum CaP‐HMP gel yield (88.83%) were 50 °C, 40 min and pH 9.6, and for the highest calcium content (97.23 mg g–1) they were 40 °C, 30 min and pH 9.7. DC‐pectin was a typical LMP with DE varying from 26.92% to 50.33%. The DE of DC‐pectin could be predicted by a model that proved significant (R² = 0.9888).
CONCLUSION
The optimum conditions were established to produce CaP gels from HMP with high yield and calcium content. Also, LMP with predictable DE can be produced following a significant model. This study provides new insights into the production and application of CaP gel. © 2021 Society of Chemical Industry.
... Bioavailability represents the nutrient's effectiveness and thereby determines the success or failure of micronutrient status in humans (24,25). Assessment of bioavailability is essential for recommending any fortified food products in a diet to assess the absorbed amount of micronutrients compared with the recommended amount. ...
Lentil (Lens culinaris Medik.) is a quick-cooking, rapidly expanding protein-rich crop with high iron (Fe) and zinc (Zn), but low bioavailability due to the presence of phytate, similar to other grains. Lentils dual fortified with Fe and Zn can significantly improve the bioavailable Fe and Zn content. Three milled lentil product types (LPTs) were fortified with Fe using NaFeEDTA [ethylenediaminetetraacetic acid iron (III) sodium salt] (Fe fortified) or Zn from ZnSO4·H2O (Zn fortified), or both (dual fortified). Fe, Zn, phytic acid (PA) concentration, and relative Fe bioavailability (RFeB%) were assessed for samples from two fortified batches (initial and for 1 year stored). Fe, Zn, and RFeB% increased significantly in two batches of samples from the three LPTs, and decreased by 5–15% after 1 year of storage. PA concentration decreased from 8 to 15% after fortification of all samples from two batches of the three LPTs but showed different patterns of influence after storage. Dual-fortified lentil fortified with 24 mg Fe and 12 mg Zn 100 g⁻¹ lentil had the highest amount of Fe and Zn, and the lowest PA concentration, and RFeB% was increased from 91.3 to 519.5%. Significant (p ≤ 0.01) Pearson correlations were observed between Fe concentration vs. PA:Fe molar ratio (MR), Fe concentration vs. RFeB%, RFeB% vs. PA:Fe MR, and Zn concentration vs. PA:Zn MR in all samples from two batches of the three LPTs. In conclusion, dual-fortified lentil can contribute significant bioavailable Fe and Zn to populations at risk of Fe and Zn deficiency.
... The bioavailability of nutrients is another key determinant of the effectiveness of dietary supplements, with larger doses of these nutrients possibly having negative effects on the absorption and metabolism of other nutrients and resulting in unpleasant adverse reactions. 46 Low compliance to long-term use of supplements has also been reported, partly due to misunderstanding of instructions, adverse reactions, and frustration about the frequency and number of pills to be taken. 47 Some supplement users may even have the fear of being labeled as sick. ...
Nonalcoholic fatty liver disease (NAFLD), a multisystem, prevalent liver disease, can be managed with lifestyle interventions, including diet, given the lack of well-established pharmacologic therapies. This review explores the different dietary approaches that have been found effective in the management of NAFLD, offering a unique resource to healthcare professionals.
... Therefore, the objective of these studies was to assess the effects of dosing schedules on iron absorption from iron-containing MNPs and oral iron supplements containing 12 mg iron given to Kenyan infants, with absorption as the primary outcome and PHep as the secondary outcome. Because iron supplements are typically more rapidly absorbed than iron fortificants (21), we anticipated that the iron supplement would cause a greater increase in PHep than the iron-containing MNP. Therefore, our hypotheses were: 1) iron absorption would be higher from morning than afternoon iron doses; 2) consumption of the iron-containing MNP would stimulate an increase in PHep that would last 24 h but not 48 h, and therefore, FIA would be higher from alternate day than from consecutive day dosing; 3) consumption of the oral iron supplement would stimulate an increase in PHep that would last 48 h but not 72 h and therefore FIA would be higher from every third day dosing than from alternate day dosing. ...
Background:
In adults, oral iron doses increase plasma hepcidin (PHep) for 24 h, but not for 48 h, and there is a circadian increase in PHep over the day. Because high PHep decreases fractional iron absorption (FIA), alternate day iron dosing in the morning may be preferable to consecutive day dosing. Whether these effects occur in infants is uncertain.
Objective:
Using stable iron isotopes in Kenyan infants, we compared FIA from morning and afternoon doses and from consecutive, alternate (every second day) and every third day iron doses.
Methods:
In prospective studies, we measured and compared FIA and the PHep response from 1) meals fortified with a 12-mg iron micronutrient powder given in the morning or afternoon (n = 22); 2) the same given on consecutive or alternate days (n = 21); and 3) a 12-mg iron supplement given on alternate days or every third day (n = 24).
Results:
In total, 65.7% of infants were anemic. In study 1, PHep did not differ between morning and afternoon (P = 0.072), and geometric mean FIA[-SD, +SD](%) did not differ between the morning and afternoon doses [15.9 (8.9, 28.6) and 16.1 (8.7, 29.8), P = 0.877]. In study 2, PHep was increased 24 h after oral iron (P = 0.014), and mean FIA [±SD](%) from the baseline dose [23.3 (10.9)] was greater than that from the consecutive day dose (at 24 h) [20.1 (10.4); P = 0.042] but did not differ from the alternate day dose (at 48 h) [20.9 (13.4); P = 0.145]. In study 3, PHep was not increased 48 and 72 h after oral iron (P = 0.384), and the geometric mean FIA[-SD, +SD](%) from doses given at baseline, alternate days, and every third day did not differ [12.7 (7.3, 21.9), 13.8 (7.8, 24.2), and 14.8 (8.8, 24.8), respectively; P = 0.080].
Conclusions:
In Kenyan infants given 12 mg oral iron, morning and afternoon doses are comparably absorbed, dosing on consecutive days increases PHep and modestly decreases iron absorption compared with alternate day dosing, and dosing on alternate days or every third day does not increase PHep or decrease absorption. This trial was registered at clinicaltrials.gov as NCT02989311 and NCT03617575.
... In turn, Brun et al. [35] reported that the best form of using chicken eggshells as a dietary supplement of Ca is to add them in the powdered form to, e.g., bread, pizza, and spaghetti, as it caused little changes in their texture and no changes in their taste. Calcium-enriched foods should have similar physical and sensory properties to their non-enriched counterparts [13,[36][37][38]. ...
Chicken eggshells can be used as an attractive dietary source of mineral compounds, including calcium (Ca). However, the effects of chicken eggshell powder (CESP) on berry fruit juices have not been studied to date. Therefore, the objective of this study was to evaluate the effect of its addition to juices from chokeberry and cranberry on their phytochemical properties. The juices were determined for contents of polyphenols (determined by ultra-efficient liquid chromatography coupled with a mass detector (UPLC-PDA-ESI-MS/MS)), macro- and microelements (by inductively coupled plasma - optical emission spectrometry (ICP-OES)), and organic acids (by high-performance liquid chromatography (HPLC-PDA)) as well as for their antioxidative activity by radical scavenging capacity (ABTS) and ferric reducing antioxidative power (FRAP) assay, color profile (CIE L* a* b* system), and sensory attributes. The study results demonstrate that CESP addition to chokeberry and cranberry juices enriched them with minerals and increased their Ca content 25.7 times and 66.3 times, respectively, compared to the control samples. Juices supplementation with CESP significantly decreased their acidity and total organic acids content as well as increased their pH value. Chokeberry and cranberry juices supplementation with 1% CESP caused no significant changes in the amount of precipitate and their color, but it significantly improved their taste. For this reason, CESP addition in the amount of up to 1% can be suggested as the optimal supplementation of berry fruit juices. The study also demonstrated that CESP addition in the amount of up to 1% caused no significant differences in the content of polyphenolic compounds and in the antioxidative activity of juices, which can be deemed important from the viewpoint of their putative health benefits. In addition, the heat treatment of juices contributed to only a 4% loss of polyphenolic compounds from the CESP-supplemented juices compared to the 6% loss from the non-supplemented juices.
... Burckhardt (2013) had detailed an update on calcium requirement, intake, absorption, deficiency and recommendations. The bioavailability of minerals is a key consideration while developing strategies for preventing mineral deficiencies through fortification (Tait and Teucher 2002). Perales et al. (2006) reported an increase in calcium bioavailability by calcium fortification of milk. ...
Milk is a valuable source of dietary calcium and it becomes important to establish whether incorporation of dietary fiber (DF), a health promoting food constituent, would lead to any undesirable impact on the bioavailability of milk calcium or not. The DF fortified spray dried partly skimmed milk powder with prestandardized fiber Blend-I (psyllium husk, oat fiber, MCC, inulin) and fiber Blend-II (psyllium husk, oat bran, wheat fiber and inulin) was subjected to rat-feeding studies to examine the possible effects on the bioavailability of milk calcium. The differences for calcium absorption and retention among diets containing DF Blend-I, DF Blend-II and cellulose (control) were found to be non-significant. It was evident that the milk calcium bioavailability of the diets containing two fiber formulations tested (at the levels studied) was at par with that of control standard diet containing only cellulose as DF. Therefore, it is reasonable to incorporate these DF blends into dairy products, and thereby add value.
... Both fortified foods and iron supplements are effective approaches used by dietitians and paediatricians alike to tackle iron deficiency problem in children (Das et al., 2013;Sreekumar, 2016). Although both options may contain similar iron forms such as ferrous fumarate and ferrous sulfate, the iron absorption and bioavailability may vary (Fairweather-Tait and Teucher, 2002;Hurrell, 2002). It must be kept in mind that iron-fortified foods should be consumed on a daily basis due to the fact that iron absorption is influenced by food composition and thus has modest iron bioavailability. ...
Aim:
To assess the suitability of iron content and the nutritional benefits of selected fortified food products marketed for 4-8 year old children in Oman.
Methods:
Forty-five fortified foods, which are available in Omani markets, were classified into four groups based on food type and composition: ready-to-eat (RTE) breakfast cereals (two groups), malted milk drinks and milk powder formulas. The nutrition panel displayed on the products' outer package was used as a source of content values for iron and other nutrients.
Results:
Among the selected products, malted milk drinks contain a significant ( p < 0.001) amount of iron that is 6.2±3.1 mg per 30 g serving (recommended daily intake for children 4-8 years old is 10 mg). The way selected products are served, with milk or water, could have a significant impact on the iron absorption and bioavailability, which is influenced by the presence of calcium and vitamin C. The values recorded from malted milk drinks and milk powder formulas were shown to have vitamin C to iron ratios of 3:1 and 8:1, respectively. Such ratios are reportedly effective in reversing the negative effect of calcium on iron absorption. Iron-fortified foods contain low to moderate amount of iron per serving and are considered more nutritious when compared to iron supplements.
Conclusion:
Iron-fortified foods can be conditionally useful to prevent or restore iron deficiency but not be relied on as an only source of iron. Hence these products must be consumed as a part of a healthy diet plan.
... High proportion of powder could dilute the flavoring ingredient such as butter, peanut butter, sugar and salt, thus reducing the intensity of those attributes in the finished product. The physical and sensory characteristics of Ca enriched foods should be similar to those of non-fortified counterparts (Fairweather and Teucher, 2002). Brun, Lupo, Delorenzi, Di Loreto, and Rigalli (2013) found that there was a small change detected in various foods fortified by Bio-Ca powder from eggshell. ...
Whole wheat cracker fortified with tuna bone bio-calcium (Bio-Ca) powder was developed as health-promoting food rich in calcium. Fortification with different levels of Bi-Ca, over the range of 0–50% of whole wheat flour (w/w) on quality and sensory properties of crackers, were determined. Color, thickness, weight and textural properties of crackers varied with the different levels of Bio-Ca powder added, but it was found that up to 30% could be added without detrimental effect on sensory properties. Scanning electron microscopic images showed that the developed crackers were less porous and had a denser structure, compared to the control. Based on scanning electron microscopy-energy dispersive X-ray spectroscopic (SEM-EDX), the cracker containing Bio-Ca powder had calcium and phosphorous distribution with higher intensity, compared to the control. The fortified crackers were rich in calcium and phosphorous with higher protein content but lower fat, carbohydrate, cholesterol and energy value, compared to the control.
... Fortification of main foods is generally accepted as an effective way for providing the daily requirements for a range of vitamins and minerals (Richardson, 1997;Fairweather and Teucher, 2002;Babarykin et al., 2004). Calcium-fortified products would be helpful in enhancement of the levels of calcium intake (Kim and Mendis, 2006), in particular for population groups with insufficient intakes of milk and dairy products due to the lactose intolerance (Jung et al., 2006;Luu and Nguyen, 2009). ...
Yellowfin tuna (Thunnus albacares) wastes were used to recover of tuna frame (TF) and to extract of tuna bone powder (TBP) by alkaline treatment. The amount of the calcium with 24.56% and 38.16% was the most abundant element in TF and TBP, respectively. Nine essential amino acids for human body; lysine, valine, leucine, isoleucine, methionine, threonine, histidine, phenylalanine and tryptophan are detected in TF and TBP. The amount of the collagen associated amino acids such as glycine, proline and hydroxyproline were high and the amount of glutamic acid, arginine, alanine, aspartic acid and serine were relatively more. The amount of the oleic acid, palmitic acid and gondoic acid were higher and the amount of hexadecatrienoic acid, γ-linolenic acid and dihomo-γ-linolenic acid were lower. The amount of the myristic acid, stearic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were also relatively more. Results demonstrated that TBP as inexpensive and environmentally friendly alternative source of calcium can be converted to the healthy value added products to increase of the amount of the calcium intake among people especially population groups with lactose intolerance.
... However, most bioavailable compounds have greater reactivity, leading to lipid peroxidation and color changes in the foodstuff (Fairweather-Tait & Teucher, 2002). ...
Finding alternatives for food fortification in a bioavailable form of iron is needed because iron deficiency leads to several diseases. Iron solubility and in vitro iron absorption were evaluated in free and complexed forms, as iron salts or peptide-iron complexes. Whey peptide-iron complexes were synthesized with various ligands (whey protein hydrolysate; its fractions >5 kDa and <5 kDa, obtained by ultrafiltration/diafiltration using a 5-kDa cut-off membrane; and whey protein isolate) and iron sources (FeCl2 and FeSO4). Iron bioaccessibility was assessed after in vitro gastrointestinal digestion, whereas iron uptake was measured indirectly as ferritin synthesis in a Caco-2 cell model. Although all complexes showed high bioaccessibility (>85%), only complexes that were synthesized with low-molecular-mass peptides (<5 kDa) and FeCl2 increased iron uptake by approximately 70% compared with FeSO4, one of the most widely used salts for fortification. Thus, this complex is an alternative for food fortification that deserves further research.
... Other nutrients found in foods can also affect the bio-availability of calcium, for example, zinc and iron (Hallberg, 1998). Therefore, it is important to consider the inter-relation of the nutrients in the diet (Fairweather-Tait & Teucher, 2002). ...
Adequate intake of calcium and phosphorus in the appropriate ratio of 1–2:1 (Ca:P), in addition to magnesium and vitamin D, is vital for bone health and development of an infant. In this feasi- bility study, the ratio of Ca:P in conjunction with vitamin D and other essential elements (Cu, Fe, K, Mg, Na, and Zn) in a range of commercial infant food products in the UK is investigated. The elemental analysis was carried out using inductively coupled plasma optical emission spectrome- try, and vitamin D levels were determined using an enzyme‐linked immunosorbent assay. The quantitative data were further evaluated, based on a standardized menu, to measure the total daily intake of an infant aged 7–12 months against the Reference Nutrient Intake. The results from the study show that the Ca:P ratio of the infant's total dietary intake was within the recommended range at 1.49:1. However, the level of intake for each of the nutrients analyzed, with the exception of sodium, was found to be above the Reference Nutrient Intake, which war- rants further investigation in relation to both micronutrient interactions and in situations where the intake of fortified infant formula milk is comprised. Finally, as the study is the first to include consumption of infant snack products, the level of total calorie intake was also calculated in order to assess the total daily estimated energy intake; the results indicate that energy intakes exceed recommendations by 42%, which may have implications for obesity.
... Interactions between the mineral salt and the food matrix may affect the bioavailability of the mineral salt. The impact of iron and calcium fortifi cation in industrialized and underdeveloped countries has been reviewed (Fairweather-Tait et al., 2002). ...
This chapter begins with a review of ingredients used as food additives, nutraceuticals and dietary supplements. It describes issues encountered in delivering dietary supplements to complement inadequate diets. It discusses challenges faced by the food industry when delivering food additives and nutraceuticals into food, and approaches that have been used to maximize the intended benefits of these ingredients without compromising food quality. It also discusses the future potential of encapsulated food additives, supplements and nutraceuticals in the food industry.
... 29 Iron bioavailability, defined as the amount of a nutrient ingested, absorbed and utilised for normal metabolic functions, is affected by numerous dietary and hostrelated factors. 29,30 Research over the last 45 years has produced highly variable results with respect to the bioavailability of iron powders (from 5% to 145% relative to the standard -ferrous sulphate). 13 This suggests that the elementary iron used in South Africa may not be readily available. ...
Objective.
To assess the effect of fortification of staple foods on the folate and iron status of women of
childbearing age.
Design.
A prospective cohort study was undertaken.
Setting.
Dikgale Demographic Surveillance Site, a rural area in the Capricorn district of Limpopo Province.
Subjects.
Non-pregnant women of childbearing age, 18 - 44 years (N=80).
Outcome measures.
Serum folate, ferritin, vitamin B12, red blood cell folate and full blood count.
Results.
The prevalence of low serum folate (<3ng/ml) in the study population was 27.6% before fortification;
after fortification, none of the women had low serum folate. Low red cell folate (<164 ng/ml) was observed in
26.4% of subjects before fortification, and in 1.9% of subjects after fortification. The prevalence of vitamin B12
deficiency (<145 pg/ml) was 6.3% during phase 1 of the study and increased to 11.3% during phase 2. Low
haemoglobin levels were present in 7.5% of women before fortification, and in 5% of women after fortification.
The percentage of women with low ferritin levels was similar before and after fortification (25%).
Conclusion.
The study shows a significant improvement in folate status in women of childbearing age
approximately 9 months after fortification of maize and wheat foodstuffs in South Africa, whereas no
improvement in iron status as measured by serum ferritin was observed
... Por outro lado, a boa biodisponibilidade apresentada pelo ferro incorporado ao iogurte pode ser compreendida pelo fato de que ácidos orgânicos, como o láctico, são considerados como sendo fatores promotores de absorção (5) (8). O ácido láctico, por sua vez, é produzido em grande escala por microrganismos durante a conversão do leite a iogurte. ...
A fortificação alimentar com ferro é uma estratégia interessante no tratamento e prevenção da anemia ferropriva. O presente estudo objetivou determinar o teor de ferro em iogurte natural e adicionado de gelatina e açúcar, preparado em recipientes de ferro e vidro bem como avaliar a aceitação e preferência dos produtos. O iogurte foi preparado com leite UHT, leite em pó e iogurte industrializado em recipientes de ferro e vidro. Após fermentação parte do produto recebeu adição de açúcar e gelatina. O teor de ferro total foi quantificado por ICP OES. Análise sensorial envolvendo 105 provadores foi realizada para determinar a aceitação e preferência dos produtos. O teor de ferro encontrado no iogurte preparado nos recipientes de vidro e de ferro foi de 0,018 e 0,882 mg de ferro por 100g, respectivamente. O iogurte com gelatina apresentou 0,037 e 1,302mg de ferro por 100g quando preparado no recipiente de vidro e de ferro, respectivamente. A preferência para o iogurte preparado na iogurteira de ferro foi baixa (29,5%) em relação ao iogurte preparado no recipiente de vidro, mas atingiu 51,5% quando adicionado de gelatina. O iogurte elaborado em iogurteira de ferro fundido mostrou ser um produto facilmente produzido domesticamente e que agrega importante quantidade de ferro, sendo seu consumo favorecido quando adicionado de gelatina e açúcar.
Metal carbonyl complexes possess among the most storied histories of any compound class in organometallic chemistry. Nonetheless, these old dogs continue to be taught new tricks. In this Feature, we review the historic discoveries and recent advances in cleaving robust bonds (e.g., C-H, C-O, C-F) using carbonyl complexes of three metals: Mn, Fe, and Co. The use of Mn, Fe, and Co carbonyl catalysts in controlling selectivity during hydrofunctionalization reactions is also discussed. The chemistry of these earth-abundant metals in the field of robust bond functionalization is particularly relevant in the context of sustainability. We expect that an up-to-date perspective on these seemingly simple organometallic species will emphasize the wellspring of reactivity that continues to be available for discovery.
Mineral and bone disorders (MBD) are common in patients with chronic kidney disease (CKD), contributing to significant morbidity and mortality. For several decades, the first-line approach to control hyperparathyroidism in CKD was by exogenous calcium loading. Since the turn of the millennium, however, a growing awareness of vascular calcification risk has led to a paradigm shift in management and a move away from calcium-based phosphate binders. As a consequence, contemporary CKD patients may be at risk of a negative calcium balance, which, in turn, may compromise bone health, contributing to renal bone disease and increased fracture risk. A calcium intake below a certain threshold may be as problematic as a high intake, worsening the MBD syndrome of CKD, but is not addressed in current clinical practice guidelines. The CKD-MBD and European Renal Nutrition working groups of the European Renal Association (ERA), together with the CKD-MBD and Dialysis working groups of the European Society for Pediatric Nephrology (ESPN) developed key evidence points and clinical practice points on calcium management in children and adults with CKD across stages of disease. These were reviewed by a Delphi panel consisting of ERA and ESPN working groups members. Main clinical practice points include a suggested total calcium intake from diet and medications of 800-1000 mg/d and not exceeding 1500 mg/d to maintain a neutral calcium balance in adults with CKD. In children with CKD, total calcium intake should be kept within the age-appropriate normal range. These statements provide information and may assist in decision-making, but in the absence of high-level evidence must be carefully considered and adapted to individual patient needs.
Many consumers believe that eating a plant-based diet will improve their health but this depends on the nature of the foods consumed. A plant-based diet mainly consisting of plant-based burgers, sausages, and nuggets consumed with refined grains, fried potatoes, snacks, sweets, and sugary beverages is unlikely to be healthy. In contrast, a plant-based diet mainly comprised of fruits, vegetables, legumes, whole grains, and nuts is likely to be much healthier. Consequently, it is important that a plant-based diet contains foods that are considered to be healthy, which usually means that they contain an appropriate macronutrient balance (carbohydrates, proteins, and fats), contain sufficient quantities of bioavailable micronutrients (vitamins, minerals, and nutraceuticals), contain high levels of dietary fibers, and are not digested too rapidly in the human gut. In addition, the impact of plant-based foods on satiety and satiation (the feelings of fullness during or after a meal), as well as metabolism (e.g., insulin response), is also important, as this may affect the total quantity of foods consumed, thereby impacting chronic diseases such as obesity and diabetes. Finally, the influence of plant-based foods on the gut microbiome is important, as the nature of the microorganisms in the colon is known to have a major impact on human health and wellbeing. The nutritional profile and health effects of plant-based foods should therefore be taken into account when creating plant-based analogs of meat, fish, egg, or dairy products. Indeed, the transition to more plant-based diets provides the food industry with an excellent opportunity to address many of the adverse health effects currently associated with the modern Western diet. In this chapter, we focus on some of the factors that need to be considered when designing the next generation of plant-based products.
Soymilk is one of the plant-based milk products containing great nutritional content and has an unpleasant beany flavour and low calcium content. In this study, different grinding methods and calcium salts fortification were applied to improve the flavour, calcium content, and stability of soymilk upon calcium addition. According to the results, preparing soymilk using the anaerobic grinding method significantly reduced the lipid oxidation (0.4781 meq peroxide/kg) and increased the sulfhydryl group content (24.25 μmol/g), compared to preparing soymilk using the conventional grinding method (0.7668 meq peroxide/kg and 15.68 μmol/g). As the results of different grinding methods, oxygen-free soymilk (OFS) has a lower amount of volatile compounds (75.04 μg/mL) than regular soymilk (RS; 966.65 μg/mL). The addition of calcium salts increased the particle diameter and viscosity of soymilk, where the significant increase was shown in calcium-enriched soymilk prepared using conventional grinding. The addition of calcium lactate reduced soymilk pH while calcium carbonate addition showed the opposite results. Soymilks enriched with calcium lactate have equivalent calcium bioavailability (28.99 and 31.21%) with cow's milk (29.47%) and significantly higher than soymilks enriched with calcium carbonate (23.73 and 22.35%). Thus, this study suggests the preparation of soymilk using the anaerobic grinding method with the addition calcium lactate as the calcium source. This combination can produce calcium-enriched soymilk with high acceptability without altering the initial sensory properties.
Iron is known as an essential nutrient in the human body. Insufficient iron uptake is easy to result in iron deficiency anemia, which is a public health problem in both developing and developed countries. Iron, complexed by iron-chelating peptides, have been proposed as a superior candidate to ionized iron for improving iron absorption and bioavailability. Nowadays, as more and more iron-chelating peptides are identified from different food sources, the iron-peptide binding mode attracts much attention. Meanwhile, many studies have been conducted on the iron-chelating peptides to make clear their iron bioavailability enhancement potential. The aim of this review is to provide an overview of research progress in food protein-derived iron-chelating peptides. The review would be of particular value for iron-peptide complexes as functional ingredients or iron supplements.
Excess oral iron in the intestinal tract usually produces reactive oxygen species via Fenton and Haber-Weiss reaction, so oxidative stress is triggered. Lipid peroxidation procedurally appears, ferroptosis, apoptosis and necrosis are often induced, subsequently, mitochondrial damage, endoplasmic reticulum dysfunction and even cell death occur. As a result, the intestinal epithelial cells are destroyed, leading to the incompleteness of intestinal mechanical barrier. Simultaneously, iron supplement can change the compositions and metabolic processes of intestinal microbes, and the intestinal inflammatory may be worsened. In principle, the easier dissociation of Fe²⁺ from oral iron supplements is, the more serious intestinal inflammation will occur. Fortunately, some interventions have been developed to alleviate these side effects. For instance, some antioxidants e.g. VE and ferulic acid have been used to prevent the formation of free radicals or to neutralize the formed free radicals. Furthermore, some new iron supplements with the ability of slow-releasing Fe²⁺, e.g. ferrous citrate liposome and EDTA iron sodium, have been successfully prepared. In order to recover the intestinal micro-ecological balance, probiotics and prebiotics, bacterial consortium transplantation, and fecal microbiota transplantation have been developed. This study is meaningful for us to develop safer oral iron supplements and to maintain intestinal micro-ecological health.
Essential elements are crucial for the interaction between genetic and physiological factors. If a dietary deficiency of these elements exists, it will lead to physiological and structural abnormalities that are preventable and which may be reversed by administration of the element. However, there are two aspects to the nutritional imbalance spectrum: (i) low intake resulting in deficiencies and (ii) high intake resulting in potential toxicity. This chapter focuses on the role of selected essential and trace-element components of foods and the recommended daily intake for different groups of age and sex, as well as the bioavailability and nutrient interactions in food.
The bioavailability of ingested components is an extremely important area of food and pharmaceutical research. The main issue is to determine which fraction of ingested nutrients or food pollutants can be truly used by the body and exert its healthy or deleterious effects. In this sense, knowledge of bioavailability is essential to estimate the quantity of a mineral that must be supplied to satisfy the requirements, since low intake from diet and deficiencies (with negative consequences for health) are found worldwide, and also to evaluate the toxicological risk of contaminant minerals. Physiological and dietetic factors, as well as food processing, can have an impact on mineral bioavailability. Accordingly, this chapter reviews the bioavailability of minerals of nutritional interest (Ca, Fe, Zn and Se) and with toxicological risk (As, Hg, Cd and Pb).
In vitro dissolution is a major indicator of potential in vivo calcium absorption. It can be used to assess the bioavailability of Ca from different sources. The aim of this study was to analyze the in vitro dissolution of calcium carbonate from the eggshell samples collected before and after the incubation period. The samples of chicken eggshell were characterized by good dissolution, better than that of precipitated CaCO3. The dissolution of the eggshell before incubation was found to be faster than that after incubation. Good dissolution (after 30 minutes both types of eggshells were dissolved in over 75%) of the chicken eggshell and the presence of other valuable microelements (boron, strontium) make this biomaterial an excellent source for dietary supplements production.
Abstract Increased Ca intake by adolescents is desirable. In order to achieve this, information on the current dietary sources of Ca by this age group is essential to enable change to build on existing habits. This paper addresses two issues: first, the dietary sources of Ca for adolescents are reported and, second, the importance of fortification of flour with Ca to present-day Ca intakes was determined. In 1990 the diets of 379 children aged 12 years were assessed using the 3 d dietary diary and interview method. Computerized food tables were used to calculate the contributions of different food groups to total Ca intake. The Ca content of eachfood was subdivided into naturally occurring Ca and Ca from fortification, and data were analysed to give the daily intake of each. The four most important sources of Ca were milk (25%), beverages (12%), puddings (10%) and bread (9%). Fortification of flour accounted for 13% of total Ca intake. When the contribution of fortification was removed, the proportion of subjects with intakes of Ca below the lower reference nutrient intake (Department of Health, 1991) increased more than fourfold, to 10% of girls and 12% of boys. Milk is contributing less to Ca intake than in the past and increased consumption should be encouraged. Ca fortification of flour remains an important source of Ca. Therefore, unless dietary habits are modified to ensure adequate Ca from other sources, increased consumption of unfortified products from outside the UK will lead to a further reduction in Ca intake.
Fortification of salt with iron has been developed by the National Institute of Nutrition (NIN) as a strategy for the control of iron deficiency anaemia (IDA) in India, similar to iodization of salt for control of iodine deficiency disorders (IDD). Stability of the iron fortified salt (IFS), its bioavailability and organoleptic evaluation of food items containing the IFS have been demonstrated. Acceptability and effectiveness of the IFS in school children and in multicentric community trials have been demonstrated. With the introduction of universal iodization of salt as a national policy in 1988, NIN has developed a formulation for double fortification (DFS) of salt with iodine and iron. The stability of the nutrients under laboratory conditions along with their bioavailability were found to be good but varying with the quality of salt used. The DFS has been evaluated in controlled trials in tribal communities and in residential school children. The findings of these studies are discussed. Overall, in these trials, DFS effectively controlled iodine deficiency but a clear impact on reducing anaemia was not demonstrated. In residential schoolchildren, increased urinary excretion of iodine as well as reduced anaemia were observed. The quality of salt has been found to be an important determinant of the stability of iodine in DFS. Further evaluation of this potentially important intervention is in progress.
The bioavailability of iron glycine added to a vegetable infant weaning food was compared with ferrous sulfate. Stable, isotopically labeled compounds (57Fe or 58Fe) were mixed into the midday meal (1.4 mg added Fe/serving) and fed to 9-mo-old infants on alternate days for 8 d. Bioavailability, expressed as a percentage of the dose consumed, was measured from isotopic enrichment of hemoglobin 14 d after the last test meal. There was no difference between iron glycine and ferrous sulfate (x+/-SEM): 9.0+/-0.7% and 9.9+/-0.8%, respectively. The effect of chelation was examined by measuring iron bioavailability of iron glycine and ferrous sulfate added to a high-phytate (310 mg/100 g) whole-grain cereal weaning food and comparing it with a lower-phytate (147 mg/100 g) vegetable food, as used in the first study. Both iron compounds had lower bioavailability from the high-phytate food, 5.2+/-0.5% for iron glycine and 3.8+/-0.9% for ferrous sulfate, than the lower-phytate food, 9.8+/-1.5% for iron glycine and 9.1+/-1.3% for ferrous sulfate. The results showed no significant difference in bioavailability between the two forms of iron when added to infant weaning foods, suggesting that the glycine complex was fully or partially dissociated in the gastrointestinal tract. It is concluded that chelation does not improve the bioavailability of iron in the presence of dietary inhibitors.
The experimental and epidemiological evidence demonstrating that Ca inhibits Fe absorption was reviewed, with the objectives of estimating the potential impact of variations in Ca intake on dietary Fe bioavailability and of providing some guidelines for predicting the effects on Fe status of recent recommendations for higher dietary Ca intake. In animal models Ca salts reduced both haem- and non-haem-Fe absorption, the effect being dependent on the amount of Ca administered rather than the Ca:Fe molar ratio; dairy products had a variable effect; factors other than Ca may have been important. In single-meal human absorption studies, both haem- and non-haem-Fe absorption was inhibited by Ca supplements and by dairy products, the effect depending on the simultaneous presence of Ca and Fe in the lumen of the upper small intestine and also occurring when Ca and Fe were given in the fasting state. The quantitative effect, although dose dependent, was modified by the form in which Ca was administered and by other dietary constituents (such as phosphate, phytate and ascorbic acid) known to affect Fe bioavailability. The mechanism by which Ca influences Fe absorption has not been elucidated. The effects of factors that modulate Fe bioavailability are known to be exaggerated in single-meal studies, and measurements based on several meals are more likely to reflect the true nutritional impact. The results of most multiple-meal human studies suggest that Ca supplementation will have only a small effect on Fe absorption unless habitual Ca consumption is very low. Outcome analyses showed that Ca supplements had no effect on Fe status in infants fed Fe-fortified formula, lactating women, adolescent girls and adult men and women. However it should be noted that the subjects studied had adequate intakes of bioavailable Fe and, except in one study, had relatively high habitual Ca intakes. Although cross-sectional analyses in Europe have shown a significant inverse correlation between Ca intake (derived primarily from dairy foods) and Fe stores, the quantitative effect was relatively small. The general conclusion is that dietary Ca supplements are unlikely to have a biologically significant impact on Fe balance in Western societies unless Ca consumption is habitually very low; however, increased consumption of dairy products may have a small negative effect that could be functionally important in pregnancy if Fe supplements are not taken. It is uncertain whether the inverse relationship between consumption of dairy products and Fe status is due entirely to increased Ca intake; substitution of milk proteins for meat may also have negative effects on Fe balance.
The nutritional requirements of contemporary humans were almost certainly established over eons of evolutionary experience and the best available evidence indicates that this evolution occurred in a high-calcium nutritional environment. The exercise and dietary patterns of humans living at the end of the Stone Age can be considered natural paradigms: calcium intake was twice that for contemporary humans and requirements for physical exertion were also greater than at present. Bony remains from that period suggest that Stone Agers developed a greater peak bone mass and experienced less age-related bone loss than do humans in the 20th Century.
A targeted, double-blind controlled iron fortification trial using Fe(111)-EDTA in masala (curry powder) was directed towards an Fe-deficient Indian population for 2 y. The Fe status of the fortified group improved more than that of control subjects. Improvement reached significance over control subjects for females in hemoglobin (p = 0.0005), ferritin (p = 0.0002), and body Fe stores (p = 0.001) and for males in ferritin (p = 0.04). The prevalence of Fe-deficiency anemia (IDA) decreased from 22 to 5% in fortified females. Premenopausal women, multipara women, and women with prolonged menstruation or initial IDA benefitted most from fortification. The mean increase in body Fe stores in females with initial IDA was 9.0 +/- 1.3 mmol, representing an increased absorption of 12 mumol/d. Fortified subjects with normal Fe status did not accumulate excessive body Fe and there was no alteration in serum Zn concentrations. Targeted fortification is a safe and effective means of combatting Fe deficiency.
Calcium absorption from two Ca salts was investigated in a crossover design using stable isotopic tracers in 12 healthy adolescents (6 males, 6 females). A Ca supplement in the form of Ca carbonate or Ca citric and malic acids (CCM) was ingested with a standardized breakfast and the order of administration was randomized. The oral supplement contained 250 mg elemental Ca, 21.8 mg of which was highly enriched 44Ca tracer. Thirty minutes later subjects received 3.6 mg 42Ca tracer intravenously. The molar concentrations of 42Ca and 44Ca tracers in a urine sample obtained 24 h after tracer administration were quantified by fast-atom-bombardment mass spectrometry and used to determine fractional absorption of the Ca from the supplement. Ca in the form of CCM had an increased fractional absorption (p less than 0.03) relative to Ca carbonate in healthy adolescents (36.2 vs 26.4%). This increase was not related to body size, sex, or indices of Ca metabolism.
To determine the anemia trends among low-income US children, hematologic measurements obtained from children aged 6 to 60 months who were enrolled in public health programs in six states that were consistently monitored by the Centers for Disease Control Pediatric Nutrition Surveillance System were studied. Overall, the prevalence of anemia has declined steadily from 7.8% in 1975 to 2.9% in 1985. The prevalence of anemia declined significantly among children seen at preenrollment screening visits, as well as those seen at follow-up visits, suggesting a generalized improvement in childhood iron nutritional status in the United States, as well as a positive impact of public health programs. To ensure that the declining trend of anemia was not a function of a change in the population of children enrolled in the surveillance system, Tennessee nutrition surveillance records were further analyzed; these records were linked with birth records to obtain detailed socioeconomic status (SES) information. Even though the SES composition remained stable from 1975 to 1984, the prevalence of anemia has declined significantly within each SES group. These findings indicate a true decline in the prevalence of anemia among low-income children that is likely the result of improvements in childhood iron nutrition.
The bioavailability in man of commercially available elemental iron powders is unknown despite their extensive use for fortification of flour. Carbonyl iron, which is widely used in Europe, is considered as one of the best reduced iron powders based on studies both in vitro and in animals. In this study, a 55Fe labeled carbonyl iron was prepared by neutron irradiation and used to fortify wheat flour. The native iron of the wheat was extrinsically labeled by 59FeCl3. Doubly labeled wheat rolls were served with different meals. The ratio of absorbed 55Fe/59Fe is a direct measure of the fraction of carbonyl iron that joins the nonheme iron pool and is made potentially available for absorption. This relative bioavailability of carbonyl iron was unexpectedly low and varied from 20 to 5% when the iron fortified wheat rolls were served with different meals. The baking process did not change the relative bioavailability nor the addition of ascorbic acid. The low and variable bioavailability of carbonyl iron in man, makes it necessary to reconsider the rationale of using elemental iron powders for the fortification of foods for human consumption.
Iron retention and its subsequent distribution from 3 g 59Fe extrinsically-labelled wholewheat four in rats given a low (8 micrograms Fe/g)- or high (566 micrograms Fe/g)-Fe diet during the previous 3 d was measured (Expt 1). The mean (with SE) proportion of Fe retained from wholewheat flour was 0.46 (0.04) in the group given the low-Fe diet and 0.15 (0.01) in the group given the high-Fe diet (P less than 0.001). There was no difference in distribution of absorbed 59Fe in the tissues examined. The procedure was repeated in rats given diets containing a range of Fe concentrations, groups 1-6 respectively: 8, 77, 136, 334, 566, 1270 micrograms Fe/g (Expt 2). The mean (with SE) proportions of Fe retained in groups 1-6 respectively were 0.60 (0.02), 0.34 (0.02), 0.30 (0.02), 0.20 (0.20), 0.17 (0.02), 0.09 (0.01). Regression analysis showed that Fe retention was a function of the logarithm of the Fe concentration of the diet consumed before the test meal (R -0.997, P less than 0.0001) where Fe retained (microgram) = 95 -28 log10 Fe concentration of diet. Rats were given a low-, medium- or high-Fe diet (8, 136 or 1270 micrograms Fe/g respectively) for 1 or 2 d instead of 3 d before measuring Fe retention from 3 g wholewheat flour (Expt 3). The mean (with SE) proportions of Fe retained in rats given the low-, medium- or high-Fe diets for 1 d were 0.45 (0.02), 0.25 (0.02) and 0.13 (0.01) (P less than 0.001) and for 2 d 0.47 (0.03), 0.31 (0.03) and 0.18 (0.02) (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
In normal subjects, a low level of metabolic acidosis and positive acid balance (the production of more acid than is excreted) are typically present and correlate in degree with the amount of endogenous acid produced by the metabolism of foods in ordinary diets abundant in protein. Over a lifetime, the counteraction of retained endogenous acid by base mobilized from the skeleton may contribute to the decrease in bone mass that occurs normally with aging.
To test that possibility, we administered potassium bicarbonate to 18 postmenopausal women who were given a constant diet (652 mg [16 mmol] of calcium and 96 g of protein per 60 kg of body weight). The potassium bicarbonate was given orally for 18 days in doses (60 to 120 mmol per day) that nearly completely neutralized the endogenous acid.
During the administration of potassium bicarbonate, the calcium and phosphorus balance became less negative or more positive--that is, less was excreted in comparison with the amount ingested (mean [+/- SD] change in calcium balance, +56 +/- 76 mg [1.4 +/- 1.9 mmol] per day per 60 kg; P = 0.009; change in phosphorus balance, +47 +/- 64 mg [1.5 +/- 2.1 mmol] per day per 60 kg; P = 0.007) because of reductions in urinary calcium and phosphorus excretion. The changes in calcium and phosphorus balance were positively correlated (P < 0.001). Serum osteocalcin concentrations increased from 5.5 +/- 2.8 to 6.1 +/- 2.8 ng per milliliter (P < 0.001), and urinary hydroxyproline excretion decreased from 28.9 +/- 12.3 to 26.7 +/- 10.8 mg per day (220 +/- 94 to 204 +/- 82 mumol per day; P = 0.05). Net renal acid excretion decreased from 70.9 +/- 10.1 to 12.8 +/- 21.8 mmol per day, indicating nearly complete neutralization of endogenous acid.
In postmenopausal women, the oral administration of potassium bicarbonate at a dose sufficient to neutralize endogenous acid improves calcium and phosphorus balance, reduces bone resorption, and increases the rate of bone formation.
(Voprosy sovremennoi pediatrii = Current pediatrics. 2007;6(1):140-142)
Osteoporosis and related fractures will be growing public health problems as the population ages. It is therefore of great importance to identify modifiable risk factors.
We investigated associations between dietary components contributing to an alkaline environment (dietary potassium, magnesium, and fruit and vegetables) and bone mineral density (BMD) in elderly subjects.
Dietary intake measures were associated with both cross-sectional (baseline) and 4-y longitudinal change in BMD among surviving members of the original cohort of the Framingham Heart Study. Dietary and supplement intakes were assessed by food-frequency questionnaire, and BMD was measured at 3 hip sites and 1 forearm site.
Greater potassium intake was significantly associated with greater BMD at all 4 sites for men and at 3 sites for women (P < 0.05). Magnesium intake was associated with greater BMD at one hip site for both men and women and in the forearm for men. Fruit and vegetable intake was associated with BMD at 3 sites for men and 2 for women. Greater intakes of potassium and magnesium were also each associated with less decline in BMD at 2 hip sites, and greater fruit and vegetable intake was associated with less decline at 1 hip site, in men. There were no significant associations between baseline diet and subsequent bone loss in women.
These results support the hypothesis that alkaline-producing dietary components, specifically, potassium, magnesium, and fruit and vegetables, contribute to maintenance of BMD.
This update focuses on the bioavailability of dietary calcium for humans. Fundamentals of calcium metabolism, intestinal absorption, urinary excretion and balance are recalled. Dietary factors, especially lactose and other milk components, influencing calcium bioavailability at intestinal and renal levels are reviewed. A critical examination of all the methods used for evaluating calcium bioavailability is made. This includes in vitro assays, classical and isotopic balances, urinary excretion, isotope labeling in the urine, plasma and bones, long term evaluation of bone mineralization and the use of biological bone markers. Importance and advantages of animal models are discussed. The state of the art in the comparative bioavailability of calcium in foods is detailed including a comparison of sources of calcium (dairy products and calcium salts) in human studies and in some animal studies, casein phosphopeptides, proteins, lactose and lactase and their relation with calcium bioavailability (in humans and rats). An update on the consumption of dairy products and bone mass is presented. Emphasis on peculiarities and advantages of calcium in milk and dairy products is given.
This study was conducted to determine the bioavailability of iron amino acid chelate (ferrochel) added to fortify breads prepared from either precooked corn flour or white wheat flour + cheese and margarine compared with the same basal breakfast enriched with either ferrous sulfate or iron-EDTA. The inhibitory effect of phytate and polyphenols on iron absorption from ferrochel was also tested. A total of 74 subjects were studied in five experiments. Iron absorption from ferrochel was about twice the absorption from ferrous sulfate (P: < 0.05). When ferrous sulfate and ferrochel were administered together or in different meals, absorption from ferrochel was about twice the absorption from ferrous sulfate (P: < 0.05). Polyphenols present in coffee and tea inhibited iron absorption in a dose-dependent manner. American-type coffee did not modify iron absorption significantly, whereas both espresso-type coffee and tea reduced iron absorption from ferrochel by 50% (P: < 0. 05). Ferrochel partially prevented the inhibitory effect of phytates. Because of its high solubility in aqueous solutions even at pH 6, its low interactions with food and high absorption, ferrochel is a suitable compound for food fortification.
As in the story of Dr Jekyll and Mr Hyde, iron (like most nutrients and particularly micronutrients) possesses both the best and the worst possible qualities. Both an inadequate supply of iron to body tissues and excessive iron accumulation within the body lead to significant morbidity. So, iron is an intriguing compound, with a wide range of benefits when it enables covering iron requirements and preventing and controlling iron deficiency (that is the Dr Jekyll’s side), but also toxicity, as it is able to induce tissue damage with formation of toxic oxygen species (that is Mr Hyde’s side). This paper focuses on results of epidemiological data related to two fundamental points in the heart of the debate, as we are faced in developed country: – are preventive measures against iron deficiency (such as iron supplementation and iron fortification) justified and are they efficient? – do they present any risks for the general or specific populations?
ABSTRACTA method of calcium fortification of milled rice was developed and tests conducted to investigate calcium distribution and retention. Milled rice (Karen variety) was soaked in 3.0% calcium lactate solution (CLS)(rice: CLS, 1.0:0.75 w/v) for 3 hr at room temperature followed by steaming 10 min at 0.68 atm, and drying to 10–11% moisture. Washing fortified rice resulted in calcium losses of ∼5%. Calcium fortified rice flour samples after dialysis, retained ∼60% of original calcium. Fortification process met U.S. standards for calcium-fortified rice (110–220 mg/100g rice) and resulted in minimal washing losses.
The importance of trace element speciation in relation to absorption and metabolism is reviewed. Availability for absorption
depends upon the chemical form that is presented to the intestinal mucosal cells, namely solubility, oxidation state and the
binding strength of ligands in the lumen of the gastrointestinal tract. For some elements, such as selenium, retention and
utilisation appear to depend upon chemical form. The need to take speciation into consideration when undertaking trace element
bioavailability studies employing isotopic labels is discussed.
To determine the effect of the differences in the content of essential and nonessential ingredients and of a standardized meal on iron bioavailability from four popular prenatal multivitamin/multimineral supplements.
Iron absorption during an eight-hour period following ingestion of a multivitamin/multimineral formulation, both fasting and postprandial, after a standardized meal, was measured in five groups of 20 pregnant women (24-32 weeks of gestation) and statistically compared. The prenatal formulations were Natalins Rx, Prenatal 1/1, Stuartnatal Plus and Prenate 90. One-A-Day (without iron) was included in the study for the control group.
The descending order of absorption, both fasting and postprandial, were Prenate 90, Stuartnatal Plus, Prenatal 1/1 and Natalins Rx. Total iron absorption for each formulation group during the postprandial phase was higher than during the fasting phase. However, the net amount of iron absorption (in both the fasting and postprandial phases) from three of the four formulations (Stuartnatal Plus, Prenatal 1/1 and Prenate 90) provided the minimal 3.0 mg of supplemental iron per day recommended by the National Academy of Science.
The observed differences in iron absorption between prenatal supplements apparently reflect the effects of the various combinations of vitamins, essential minerals and additives. The absolute amount of elemental iron contained in a prenatal multivitamin/ multimineral formulation does not ensure availability.
Kidney International aims to inform the renal researcher and practicing nephrologists on all aspects of renal research. Clinical and basic renal research, commentaries, The Renal Consult, Nephrology sans Frontieres, minireviews, reviews, Nephrology Images, Journal Club. Published weekly online and twice a month in print.
Calcium supplements are widely used for the treatment of osteoporosis. The bioavailability of these preparations is unknown. Because poor tablet dissolution accounts for a majority of drug bioavailability problems, we determined the in vitro dissolution at 30, 60, and 90 minutes of 27 commercially available calcium carbonate supplements using the method of the U.S. Pharmacopoiea. At 30 minutes, five preparations (18%) were more than 75% dissolved, four (15%) between 33 and 74%, and the remaining 18 (67%) were less than 33% dissolved. After 90 minutes, 17 (63%) of the preparations were less than 50% dissolved. Dissolution correlated negatively with the weight of filler (noncalcium carbonate material in the tablet) (rs = -0.51, P less than 0.01) but not with tablet hardness or cost. Similar to previous studies, we also found no correlation of dissolution with the stated calcium content, chemical source of calcium carbonate (oyster shell or chemical precipitate), or retail source. We conclude that there is a wide range of in vitro dissolution among the calcium carbonate preparations tested, and that the filler is an important determinant of the dissolution of these tablets. These results raise concern about the bioavailability of the calcium in these preparations and may have important implications for the therapeutic use of the various calcium carbonate supplements.
The influence of calcium supplements on the absorption of dietary nonheme iron and of iron supplements was evaluated in 61 normal volunteer subjects by use of a double-radioisotope technique. When taken without food, calcium carbonate did not inhibit the absorption of ferrous sulphate with doses of either 300 mg Ca and 37 mg Fe or 600 mg Ca and 18 mg Fe. However, at the latter levels, calcium citrate and calcium phosphate reduced iron absorption significantly by 49% and 62%, respectively. All calcium supplements inhibited absorption of the iron supplement when taken with food. The absorption of dietary nonheme iron was also inhibited by all three supplements. This inhibition was less pronounced from a meal of high iron availability and low calcium content (28%) than from a breakfast meal of low iron availability and high calcium content (55%). These results suggest that taking regular calcium supplements with meals makes it more difficult for women to meet their daily iron requirement.
Fractional absorption of seven chemically defined calcium sources was measured in normal adult women under standardized load conditions. Solubility of the sources in water at neutral pH ranged from a low of 0.04 mM to a high of 1500 mM. The relationship of solubility to absorbability was weak. In the range from 0.1 to 10 mM, within which most calcium supplement sources fall, there was no detectable effect of solubility on absorption. Data from four food sources are presented for comparison. Absorbability of food calcium was not clearly related to absorbability of the dominant chemical form in the food concerned. These findings suggests that (1) even under controlled, chemically defined conditions, solubility of a source has very little influence on its absorbability; and (2) absorbability of calcium from food sources is determined mainly by other food components.
Calcium supplements are widely used, yet many questions remain as to the absorption of various calcium salts. Because the solubility of many calcium salts is dependent upon pH, the type of salt used, the condition of the patient, and the time of administration should be considered. Studies show that many calcium supplements on the market today do not meet standards of quality established in the "U.S. Pharmacopeia" (USP). Consumers must be discerning about the products they purchase. Calcium supplements should be taken with meals to ensure solubility. Calcium carbonate, and particularly tribasic calcium phosphate tablets, are not recommended for patients with achlorhydria. Calcium tablets, like almost all drugs, should be taken with 8 ounces of water or other liquid.
Calcium nutritional status among some groups in the United States is suboptimal when judged by calcium intakes and the high prevalence of osteoporosis. Unfortunately, however, it is not clear that increases in calcium intake will have a significant impact on osteoporosis or other chronic diseases that have been linked to calcium nutriture. There is still considerable controversy surrounding the issue of calcium Recommended Dietary Allowances (RDAs). The body's ability to adapt to varying levels of calcium intakes, the lack of sensitive indicators of calcium status, and the complexity and slow progression of chronic diseases such as osteoporosis make it very difficult to establish the role of diet regarding this. Great progress has been made in the study of calcium absorption. Much is known about the mechanisms involved in calcium absorption and its regulation. Thus, a rapidly advancing field and further developments may be invaluable to one's understanding of the role of diet in calcium nutrition.
A total of 526 absorption studies, using both the double‐isotope and balance‐based methods, were performed in 189 middle‐aged women in good general health. The study extended over 17 years of observation, with most subjects studied from two to four times at 5 year intervals. Each study was done on the woman's own self‐selected calcium intake and was carried out under inpatient, metabolic balance controls.
There was a highly significant inverse correlation between calcium intake and absorption fraction, with the best fit provided by an hyperbola in which absorption fraction is approximately inversely proportional to the square root of intake. The range of absorptive performance was very broad at all intake levels. Mean absorption fraction declined from a value of 0.45 at very low intakes (approximately 200 mg Ca per day) to approximately 0.15 at intakes above 2000 mg/day. There was a highly significant fall in absorption efficiency with age, amounting to approximately 0.0021 per year and a one‐time decrease, amounting to approximately 0.022 at the time of menopausal estrogen loss.
Calcium supplementation is recommended as a prophylaxis against bone loss. This study was performed to determine the dose dependency of calcium absorption in an attempt to derive an optimum dose schedule. Using the well-described oral calcium load technique, we measured the calcium absorption from three different calcium doses (0.5, 1.0, and 2.0 g) of both calcium carbonate and calcium citrate administered to 21 normal subjects (4 men and 17 women, 22-60 years). Nine subjects underwent two additional loads with 0.2 g of elemental calcium as calcium carbonate and as calcium citrate. The intestinal calcium absorption from calcium carbonate and calcium citrate was estimated from the rise in urinary calcium following oral ingestion of the respective calcium salt. The increment in urinary calcium post-load, reflective of intestinal calcium absorption, rose rapidly from 0 to 0.5 g calcium loads with only slight subsequent increases from the 0.5 g to 2.0 g calcium doses. Thus, results indicate that 0.5 g of calcium is the optimum dose of either calcium salt. Moreover, the increment in urinary calcium post-load was higher from calcium citrate than from calcium carbonate at all four dosage levels. The increment in urinary calcium (during the second 2 hr) following calcium citrate load (0.5 g calcium) was 0.104 +/- 0.096 mg/dl glomerular filtrate (GF), which was higher than that of 0.091 +/- 0.068 mg/dl GF obtained from 2.0 g calcium as calcium carbonate. These results confirm the superior calcium bioavailability from calcium citrate as compared with calcium carbonate.(ABSTRACT TRUNCATED AT 250 WORDS)
Whole milk, chocolate milk, yogurt, imitation milk (prepared from dairy and nondairy products), cheese, and calcium carbonate were labeled with 45Ca and administered as a series of test meals to 10 healthy postmenopausal women. Carrier Ca content of the test meals was held constant at 250 mg and subjects fasted before each meal. The absorbability of Ca from the six sources was compared by measuring fractional absorption by the double isotope method. The mean absorption values for all six sources were tightly clustered between 21 and 26% and none was significantly different from the others using one-way analysis of variance. We conclude that none of the sources was significantly superior or inferior to the others.
To determine the long-term effects of calcium supplements or placebo on bone density in healthy women at least 3 years postmenopause.
Eighty-six women from our previously reported 2-year study agreed to continue on their double-blind treatment allocation (1 g elemental calcium or placebo) for a further 2 years, with 78 women (40 on placebo) reaching the 4-year end point. Median (interquartile range) dietary calcium intakes for the whole group were 700 mg (range 540 to 910) per day at baseline, 670 mg (range 480 to 890) per day at 2 years, and 640 mg (range 460 to 880) per day at 4 years. The bone mineral density (BMD) of the total body, lumbar spine, and proximal femur was measured every 6 months by dual-energy, x-ray absorptiometry.
There was a sustained reduction in the rate of loss of total body BMD in the calcium group throughout the 4-year study period (P = 0.002), and bone loss was significantly less in the calcium-treated subjects in years 2 through 4 also (difference between groups 0.25% +/- 0.11% per year, P = 0.02). In the lumbar spine, bone loss was reduced in the calcium group in year 1 (P = 0.004), but not subsequently. There was, however, a significant treatment effect at this site over the whole 4-year period (P = 0.03). In the proximal femur, the benefit from calcium treatment also tended to be greater in the first year and was significant over the 4-year study period in the femoral neck (P = 0.03) and the trochanter (P = 0.01). Nine symptomatic fractures occurred in 7 subjects in the placebo group and 2 fractures in 2 subjects receiving calcium (P = 0.037).
Calcium supplementation produces a sustained reduction in the rate of loss of total body BMD in healthy postmenopausal women.
A 32-mo-long, double-blind field study involving one highland control community receiving only vitamin A-fortified sugar and three vitamin A- and FeNaEDTA-sugar-fortified communities, two in the lowlands and one in the highlands of Guatemala, was undertaken to test the effectiveness of this approach in controlling iron deficiency. The communities' population ranged between 1200 and 17000. Sugar fortified with 1 g FeNaEDTA and 15 mg retinol as retinyl palmitate/kg was stable, did not segregate, and was well accepted by the communities. The impact of fortification on iron nutrition was estimated at 8, 20, and 32 mo of intervention. All pregnant women and subjects with severe anemia received supplements or treatment and were excluded from the analysis. Iron stores in the fortified communities increased significantly except for women 18-48 y of age in one lowland community and > 49 y in the highland community. Iron stores in the control community remained unchanged except for a rise among adult males.
Increased intake of calcium has been recently recommended by a National Institutes of Health (NIH) Consensus Development Panel on Optimal Calcium Intake. However, high intakes of dietary calcium can inhibit iron absorption if both are present in the same meal. The mechanism for the calcium-iron interaction is not known. A recent study has demonstrated that separating foods high in calcium from meals high in iron can prevent some of the calcium-induced inhibition of iron absorption. The feasibility of changing the nature of meals or the timing of calcium supplementation to adjust for this phenomenon is untested.
Bone resorption shows a circadian rhythm in human subjects, but the physiological mechanisms underlying this rhythm are unknown. We compared the circadian rhythm of bone collagen degradation in 18 premenopausal women before and after oral calcium supplementation (1000 mg calcium for 14 days). Subjects were randomized to receive calcium at either 0800 h or 2300 h. Continuous 48-h urine collections and 1 day of 4-h urine collections were obtained before and after the 14-day supplementation period. We measured urinary deoxypyridinoline (Dpd) and the cross-linked N-telopeptide of type I collagen (NTx) as biochemical markers of bone resorption. There was a significant effect of time of day on excretion of Dpd and NTx (analysis of variance, P < 0.001) with peak excretion between 0300-0700 h and a nadir between 1500-1900 h. The mean amplitude (peak to trough) was similar for Dpd and NTx (70.3% and 63.3%, respectively). Evening calcium supplementation resulted in marked suppression of the nocturnal increase in Dpd and NTx and reversed the usual nocturnal increase in the level of parathyroid hormone. In contrast, morning calcium supplementation had no significant effect on the circadian rhythm of Dpd or NTx. Evening calcium supplementation suppressed overall daily excretion of Dpd by 20.1% (P = 0.03) and NTx by 18.1% (P = 0.03). Morning calcium supplementation had no significant effect on overall daily excretion of either Dpd or NTx. We conclude that evening calcium supplementation suppresses the circadian rhythm of bone resorption. The daily rhythm of PTH secretion or calcium intake is likely to be an important determinant of this rhythm. Experimental protocols designed to investigate the effect of calcium supplementation on bone mineral density should take the timing of supplementation into account.
There are more than a dozen commonly prescribed calcium supplements and hundreds of different formulations commercially available. Numerous factors need to be considered when selecting a calcium preparation. Physical properties such as solubility, interference from coingested medications or foodstuffs, dosage, and timing can all affect the bioavailability of calcium. Medical conditions such as lactose intolerance, impaired gastric acid secretion, and high risk profile for kidney stone formation may impact on selection of a calcium supplement. This article will review the available literature and make general recommendations for the optimal use of calcium preparations.
To determine whether augmentation of dietary calcium is effective in the prevention of early postmenopausal bone loss.
Three-arm, placebo-controlled, randomized parallel trial. The study duration was 2.9 +/- 1.1 (SD) years.
General community.
118 healthy, white women 3 to 6 years after spontaneous menopause, recruited by community announcement.
Random allocation to daily intake of 1700 mg of calcium (calcium carbonate given in divided doses with meals); placebo; or conjugated equine estrogens (0.625 mg; days 1 to 25), progesterone (10 mg; days 16 to 25), and 1700 mg of elemental calcium daily. Each participant received 400 IU of vitamin D daily.
Total body calcium measured by delayed gamma neutron activation analysis and whole-body counting; bone mineral density of the spine, femur, and radius measured by photon absorptiometry.
Bone mineral density declined in the placebo group for the lumbar spine (-2.1%/y; 95% Cl, -3.3 to -0.9), femoral neck (-2.0%/y; Cl, -2.6 to -1.2), trochanter (-1.6%/y; Cl, -2.4 to -0.8), Ward triangle (-2.7%/y; Cl, -3.7 to -1.7), and total body calcium (-2.0%/y; Cl, -2.2 to -1.8). Rates of change were intermediate for calcium augmentation compared with placebo and estrogen-progesterone-calcium but statistically significant compared with placebo for total body calcium (-0.5%/y; Cl, -0.9 to -0.1; P = 0.006) and the femoral neck (-0.8%/y; Cl, -1.4 to -0.2; P = 0.03).
Although less effective than estrogen-progesterone-calcium, calcium augmentation alone significantly retards bone loss from the femoral neck and improves calcium balance in recently postmenopausal women. Dietary calcium augmentation should be recommended as a strategic option in helping to prevent early postmenopausal bone loss.
The finding that the link between polymorphism at the vitamin D receptor (VDR) gene and rates of bone loss from the femoral neck in postmenopausal women is enhanced at low calcium intakes suggests that intestinal calcium absorption is a site of differential action of the VDR alleles. 1,25-Dihydroxyvitamin D [1,25-(OH)2D] and its receptor mediate active calcium transport, the major mechanism of calcium absorption at low calcium intakes. We compared fractional calcium absorption in healthy late postmenopausal women with (bb) and without (BB) the BSM-1 restriction site. In 60 women (26 BB and 34 bb), we measured calcium absorption and plasma 1,25-(OH)2D after 2 weeks on a high (1500 mg/day) and 2 weeks on a low (< 300 mg/day) calcium intake. The mean 45Ca absorption indexes were similar in the two groups on the high calcium intake [19.01 +/- 1.12% (+/- SEM)/L in BB and 20.45 +/- 0.97%/L in bb; P = 0.346] and differed significantly on the low calcium intake (20.57 +/- 1.10%/L vs. 23.66 +/- 0.95%/L; P = 0.044). Calcium restriction induced similar percent increases in plasma 1,25-(OH)2D, but the BB group had a smaller increase in the fractional 45Ca absorption index [7.8 +/- 3.8% (+/- SEM) vs. 20.7 +/- 3.3% in bb; P = 0.016; increments adjusted for initial absorption value]. In conclusion, compared to women with the bb variants, women with BB allelic variants of the VDR have reduced calcium absorption efficiency on low calcium intake, consistent with a functional defect in the intestinal VDR. The impact of this heritable difference is reduced at higher calcium intakes.
Increased Ca intake by adolescents is desirable. In order to achieve this, information on the current dietary sources of Ca by this age group is essential to enable change to build on existing habits. This paper addresses two issues: first, the dietary sources of Ca for adolescents are reported and, second, the importance of fortification of flour with Ca to present-day Ca intakes was determined. In 1990 the diets of 379 children aged 12 years were assessed using the 3 d dietary diary and interview method. Computerized food tables were used to calculate the contributions of different food groups to total Ca intake. The Ca content of each food was subdivided into naturally occurring Ca and Ca from fortification, and data were analysed to give the daily intake of each. The four most important sources of Ca were milk (25%), beverages (12%), puddings (10%) and bread (9%). Fortification of flour accounted for 13% of total Ca intake. When the contribution of fortification was removed, the proportion of subjects with intakes of Ca below the lower reference nutrient intake (Department of Health, 1991) increased more than fourfold, to 10% of girls and 12% of boys. Milk is contributing less to Ca intake than in the past and increased consumption should be encouraged. Ca fortification of flour remains an important source of Ca. Therefore, unless dietary habits are modified to ensure adequate Ca from other sources, increased consumption of unfortified products from outside the UK will lead to a further reduction in Ca intake.
To describe dietary habits and use of mineral supplements in relation to nutrient recommendations and anaemia.
a population-based cohort study.
2665 men and 3878 women, born between 1926 and 1945, randomly invited and participating in the prospective 'Malmö Diet and Cancer study' during 1991-1992.
The diet was assessed using a combined 7-day menu book for hot meals, beverages and supplements and a quantitative food frequency questionnaire for other foods. Anaemia was defined as haemoglobin < or = 131 g/l for men and < or = 115 g/l for women.
Intake of mineral supplements were reported by 19% of the men and 31% of the women. Less than 0.2% had intakes of iron and selenium above highest recommended Swedish long-term intakes. The percentage of women with intake below nutrient recommendations were: zinc and selenium (60%); magnesium (35%); calcium (21%) and iron (70%, premenopausal). The corresponding values for men were: zinc, selenium and magnesium (33-47%); calcium and iron (5%). The median contribution of calcium from supplements was less than 110 mg. Supplement users had higher intakes of fish, fruits, vegetables and tea and lower intakes of coffee and meat. The iron intake was correlated to haemoglobin levels, and iron supplementation constituted about 45% of the intake. Three per cent of premenopausal women had anaemia as did less than 2% of postmenopausal women.
A substantial number had mineral intake below present recommendations despite supplement use. The nutrient content of some supplements could be improved, especially calcium. Iron supplementation among postmenopausal women and men are questionable.
High calcium intake during childhood has been suggested to increase bone mass accrual, potentially resulting in a greater peak bone mass. Whether the effects of calcium supplementation on bone mass accrual vary from one skeletal region to another, and to what extent the level of spontaneous calcium intake may affect the magnitude of the response has, however, not yet been clearly established. In a double-blind, placebo-controlled study, 149 healthy prepubertal girls aged 7.9+/-0.1 yr (mean+/-SEM) were either allocated two food products containing 850 mg of calcium (Ca-suppl.) or not (placebo) on a daily basis for 1 yr. Areal bone mineral density (BMD), bone mineral content (BMC), and bone size were determined at six sites by dual-energy x-ray absorptiometry. The difference in BMD gain between calcium-supplemented (Ca-suppl.) and placebo was greater at radial (metaphysis and diaphysis) and femoral (neck, trochanter, and diaphyses) sites (7-12 mg/cm2 per yr) than in the lumbar spine (2 mg/cm2 per yr). The difference in BMD gains between Ca-suppl. and placebo was greatest in girls with a spontaneous calcium intake below the median of 880 mg/d. The increase in mean BMD of the 6 sites in the low-calcium consumers was accompanied by increased gains in mean BMC, bone size, and statural height. These results suggest a possible positive effect of calcium supplementation on skeletal growth at that age. In conclusion, calcium-enriched foods significantly increased bone mass accrual in prepubertal girls, with a preferential effect in the appendicular skeleton, and greater benefit at lower spontaneous calcium intake.
Inadequate dietary intake of calcium and vitamin D may contribute to the high prevalence of osteoporosis among older persons.
We studied the effects of three years of dietary supplementation with calcium and vitamin D on bone mineral density, biochemical measures of bone metabolism, and the incidence of nonvertebral fractures in 176 men and 213 women 65 years of age or older who were living at home. They received either 500 mg of calcium plus 700 IU of vitamin D3 (cholecalciferol) per day or placebo. Bone mineral density was measured by dual-energy x-ray absorptiometry, blood and urine were analyzed every six months, and cases of nonvertebral fracture were ascertained by means of interviews and verified with use of hospital records.
The mean (+/-SD) changes in bone mineral density in the calcium-vitamin D and placebo groups were as follows: femoral neck, +0.50+/-4.80 and -0.70+/-5.03 percent, respectively (P=0.02); spine,+2.12+/-4.06 and +1.22+/-4.25 percent (P=0.04); and total body, +0.06+/-1.83 and -1.09+/-1.71 percent (P<0.001). The difference between the calcium-vitamin D and placebo groups was significant at all skeletal sites after one year, but it was significant only for total-body bone mineral density in the second and third years. Of 37 subjects who had nonvertebral fractures, 26 were in the placebo group and 11 were in the calcium-vitamin D group (P=0.02).
In men and women 65 years of age or older who are living in the community, dietary supplementation with calcium and vitamin D moderately reduced bone loss measured in the femoral neck, spine, and total body over the three-year study period and reduced the incidence of nonvertebral fractures.
The amount of calcium absorbed in the intestine depends on habitual calcium intake. When intake is low, active transcellular calcium transport in the duodenum is upregulated and a larger proportion of calcium is absorbed by the active process than by the passive paracellular process that prevails in the jejunum and ileum. Bioavailability of the calcium source-digestibility and solubilization-plays a role under conditions of low calcium intake but is relatively unimportant when calcium intakes are high (e.g. >800 mg/d in people). Vitamin D intake is a second factor, as active calcium transport is directly and proportionally dependent on the presence in the intestinal cell of calbindin D9k, the biosynthesis of which is totally vitamin D dependent. Passive absorption in jejunum and ileum is the major absorptive process when calcium intake is adequate or high. Passive calcium absorption is a complicated function of solubility in the distal small intestine, the length of sojourn of the chyme in a given intestinal segment, and the rate of paracellular diffusion from lumen to lymph and blood. Calcium that reaches the large intestine undergoes absorption there by both active and passive processes. Probably no more than 10% of total calcium absorption takes place in the large intestine, whether calcium intake is low or high. Calcium absorption by the large bowel can assume nutritional importance under conditions of significant small bowel resection.
Micronutrient deficiencies remain common in preschool children in developing countries. Interventions focus on single micronutrients and often lack effectiveness. Weekly instead of daily supplementation may improve effectiveness.
The efficacy of weekly and daily supplementation in reducing anemia prevalence and in improving the zinc, vitamin A, and growth status of 6-24-mo-old Vietnamese children was investigated.
In this double-blind, placebo-controlled trial, the daily group (n = 55) received 8 mg elemental Fe (as iron sulfate), 5 mg elemental Zn (as zinc sulfate), 333 microg retinol, and 20 mg vitamin C 5 d/wk for 3 mo. The weekly group (n = 54) received 20 mg Fe, 17 mg Zn, 1700 microg retinol, and 20 mg vitamin C once a week. A third group (n = 54) received a placebo only. Venous blood samples were collected at the start and end of the supplementation period and anthropometric measurements were taken at the start and 3 mo after the end of supplementation.
At baseline, 45.6% of subjects had hemoglobin concentrations < 110 g/L, 36.3% had zinc concentrations < 10.71 micromol/L, and 45.6% had retinol concentrations <0.70 micromol/L. Hemoglobin, retinol, and zinc concentrations of both the weekly and daily groups increased similarly compared with the placebo group (P < 0.001). There was no significant difference in growth between the supplemented groups and the placebo group. However, the height-for-age of subjects stunted at baseline increased with z scores of 0.48 (P < 0.001) and 0.37 (P < 0.001) for the daily and weekly groups, respectively.
Weekly and daily supplementation improved hemoglobin, zinc, and retinol concentrations similarly. Neither intervention affected growth of the overall population, but growth of children stunted at baseline was improved through both types of supplementation.
The vitamin D receptor (VDR) gene has been implicated as one of the major genetic components of osteoporosis. We evaluated the relationship between markers of mineral status and restriction fragment length polymorphisms of the VDR gene in 72 healthy children age 7-12 years. Using stable isotope techniques and dual-energy X-ray absorptiometry, we measured dietary calcium absorption, bone calcium deposition rates, and total body bone mineral density (BMD). The Fok1 polymorphism at the VDR translation initiation site was significantly associated with BMD (p = 0.02) and calcium absorption (p = 0.04). Children who were FF homozygotes had a mean calcium absorption that was 41.5% greater than those who were ff homozygotes and 17% greater absorption than Ff heterozygotes. BMD was 8.2% greater in the FF genotype than the ff genotype and 4.8% higher than the Ff genotype. These results suggest a substantial relationship between the VDR gene and bone metabolism at one or more levels, including dietary absorption of calcium and BMD in growing children.
Many gaps exist in our understanding of the role of nutrition and other lifestyle variables during the growing years on lifelong bone health. The difficulty in measuring bone changes during growth is a major barrier to our understanding of environmental effects. Changes in bone size are difficult to monitor with two-dimensional images such as those obtained by bone densitometry. Apparent bone density changes may reflect changes in bone size rather than bone density. Volumetric bone density measures, if they can be made at appropriate sites with acceptable radiation exposure, will provide the next generation of outcome measures for assessing interventions. Quantitative ultrasound measures are being explored for use in children as a potential measure of bone quality, but the interpretation of the measures is as of yet unknown. It is difficult to follow the effects of adolescent nutrition into adulthood. Most work in children is observational in nature, rather than involving a rigorous intervention. Published randomized placebo-controlled trials are relatively short in duration. It is unknown whether short term increases in the rate of bone accretion due to dietary interventions such as calcium result in greater increases in peak bone mass or if the peak is merely achieved earlier. During the pubertal growth spurt, hormonal changes may overwhelm any lifestyle interventions, as seems to be the situation during menopause, a much more studied phenomenon. We know so little about interactions of nutrients with other parameters during growth. Important areas for further research include nutrient-gene interactions, nutrient-exercise interactions, and nutrient-nutrient interactions. How do genetics determine who will respond to dietary supplementation? Will exercise increase bone size without sufficient calcium? Does an active lifestyle modify nutrient requirements? When considering the role of childhood and adolescent nutrition in lifelong bone health, we may not know precise requirements, but the risks lie with insufficient nutrient intakes, with the exception of energy. Therefore, clinicians should take an active role in assessing the diets of all patients, but especially for adolescents whose skeletal demands are so great. Research on behavior modification to achieve appropriate lifestyle choices in this age group is urgent. Strategies to instill healthy habits before this age are equally important, and they may be more effective. The benefits are potentially great. Variations in calcium nutrition in early life may account for as much as 50% of the difference in hip fracture rates in postmenopausal years (31). Taking calcium-rich products with every meal goes a long way toward ensuring that requirements are met for many bone-related nutrients, including calcium, magnesium, phosphorus, and vitamin D. However, we need more alternative strategies for many individuals, including fortified foods and palatable supplements. Evidence is compelling that inadequate nutrition during puberty results in suboptimal peak bone mass, which, in turn, increases the risk of fracture in childhood and later in life.
Health authorities recommend that populations consume a diet providing sufficient iron, and in order to prevent iron deficiency, a number of countries have fortified certain foods with iron. In Denmark, flour was fortified with iron from 1954 until 1987, at which time the mandatory fortification was stopped. This study examines the effect of iron fortification on iron status by comparing the intake of iron with serum ferritin over time and in relation to the removal of flour fortification.
In a cohort of 238 Danish men and women, at baseline ages 35-65 years, dietary intake and serum ferritin were measured, first in 1987/1988 and again in 1993/1994.
In 1987/1988 the fortification may have supplied up to 25% of total iron intake, and without this enrichment some 35% of the men and 73% of the women may have had iron intakes lower than 10 mg/day. Assuming that no flour was enriched, iron intake was constant during the 6-year study period. Despite this, after flour fortification was stopped in 1987, serum ferritin increased among both men and postmenopausal women.
Considering that mandatory iron fortification of flour affects the entire population, including subjects who are at risk for chronic diseases because of too-high iron stores, the decision to stop the mandatory fortification in Denmark seems to have been well-founded.
This 7-mo double-blind study compared the efficacy of two iron supplementation schemes in improving iron nutrition among 116 healthy fertile-age women. They were randomly distributed in three groups, receiving: Group 1, iron + folate (60 mg and 250 microg, respectively) daily for 3 mo (currently recommended scheme), and folate (250 microg) weekly the subsequent 4 mo. Group 2, folate daily, and 60 mg iron only once weekly for 3 mo, and then weekly iron + folate for 4 mo. Group 3, folate daily for 3 mo and then weekly for 4 mo. At baseline, 16% had depleted stores (plasma ferritin <15 microg/L) and 16% had hemoglobin levels <125 g/L. Eight percent had hemoglobin levels <120 g/L. In Group 1 hemoglobin and ferritin increased at 3 mo but returned to near basal conditions after 4 mo of weekly folate. In Group 2, hemoglobin and ferritin increased progressively throughout the 7 mo but mostly after 3 mo. Group 3 did not change. Side effects were highest with daily iron. Weekly iron supplementation over 7 mo (30 doses) improved and sustained iron nutrition at least as effectively and was better tolerated than 90 daily iron supplements consumed during 3 mo.
There is a need to determine whether iron absorption from iron amino acid chelates is protected from inhibition by dietary phytate and regulated normally by iron status.
The objective of this study was to compare iron absorption from ferrous sulfate, ferrous bisglycinate, and ferric trisglycinate in whole-maize meal; to determine whether iron from ferrous bisglycinate and ferrous sulfate exchanges in the intestinal pool; and to assess iron absorption from ferrous bisglycinate and ferric trisglycinate over a range of iron statuses.
In study 1A, 10 iron-sufficient men consumed ferrous sulfate-fortified whole-maize meal porridge equilibrated with (59)Fe-sulfate on day 1 and (55)Fe-bisglycinate on day 2. In study 1B, these volunteers consumed ferrous sulfate-fortified porridge equilibrated with (59)Fe-sulfate and (55)Fe-bisglycinate simultaneously. In studies 2A and 2B, iron absorption from 3 mg Fe as (59)Fe-ascorbate, (55)Fe-bisglycinate, or (59)Fe-trisglycinate in water and in porridge was compared in 23 subjects with a range of iron statuses. Iron absorption was determined from blood radioactivity on day 16.
In study 1A, geometric mean iron absorption from ferrous bisglycinate was 6.0% (range: 2.6-13.6%), 4 times higher than that from ferrous sulfate (1. 7%; range: 1.0-3.3%; P < 0.05). In study 1B, absorption from neither source was different from that in study 1A. In studies 2A and 2B, absorption from all sources was strongly inversely related to serum ferritin, with geometric means of 32.5% (iron ascorbate), 9.1% (bisglycinate), and 15.3% (trisglycinate). Iron from ferric trisglycinate was poorly absorbed (2.3%; range: 0.5-9.2%) from maize.
In whole-maize meal, iron from ferrous bisglycinate is better absorbed than is iron from ferrous sulfate and does not exchange with iron from maize or ferrous sulfate in the intestinal pool. Absorption of iron from bisglycinate and trisglycinate is regulated normally by iron status.
The chronic low-grade metabolic acidosis that occurs in various renal disorders and in normal people, and that is related both to dietary net acid load and age-related renal functional decline, may contribute to osteoporosis by increasing urine calcium excretion. Administration of potassium (K) alkali salts neutralizes acid and lowers urine calcium excretion. Urine calcium excretion also can be reduced by the administration of thiazide diuretics, which are often given with supplemental K to avoid hypokalemia. We determined whether the K alkali salt potassium bicarbonate (KHCO3) and the thiazide diuretic hydrochlorothiazide (HCTZ) combined is more effective in reducing urinary calcium than KHCO3 alone or HCTZ combined with the conventionally coadministered nonalkalinizing K salt potassium chloride (KCl).
Thirty-one healthy men and women aged 50 or greater were recruited for a four-week, double-blind, randomized study. After a baseline period of 10 days with three 24-hour urine and arterialized blood collections, subjects were randomized to receive either HCTZ (50 mg) plus potassium (60 mmol daily) as either the chloride or bicarbonate salt. Another 19 women received potassium bicarbonate (60 mmol) alone. After two weeks, triplicate collections of 24-hour urines and arterialized bloods were repeated.
Urinary calcium excretion decreased significantly in all groups. KHCO3 alone and HCTZ + KCl induced similar decreases (-0.70 +/- 0.60 vs. -0.80 +/- 1. 0 mmol/day, respectively). Compared with those treatments, the combination of HCTZ + KHCO3 induced more than a twofold greater decrease in urinary calcium excretion (-1.8 +/- 1.2 mmol/day, P < 0. 05). Both HCTZ + KHCO3 and KHCO3 alone reduced net acid excretion significantly (P < 0.05) to values of less than zero.
KHCO3 was superior to KCl as an adjunct to HCTZ, inducing a twofold greater reduction in urine calcium excretion, and completely neutralizing endogenous acid production so as to correct the pre-existing mild metabolic acidosis that an acid-producing diet usually induces in older people. Accordingly, for reducing urine calcium excretion in stone disease and osteoporosis, the combination of HCTZ + KHCO3 may be preferable to that of HCTZ + KCl.