Safety evaluation of ferrous bisglycinate chelate

Improvement of in vivo iron bioavailability using mung bean peptide-ferrous chelate

There is an increasing amount of research into the development of a third generation of iron supplementation using peptide-iron chelates. Peptides isolated from mung bean were chelated with ferrous iron (MBP-Fe) and tested as a supplement in mice suffering from iron-deficiency anemia (IDA). Mice were randomly divided into seven groups: a group fed the normal diet, the IDA model group, and IDA groups treated with inorganic iron (FeSO4), organic iron (ferrous bisglycinate, Gly-Fe), low-dose MBP-Fe(L-MBP-Fe), high-dose MBP-Fe(H-MBP-Fe), and MBP mixed with FeSO4 (MBP/Fe). The different iron supplements were fed for 28 days via intragastric administration. The results showed that MBP-Fe and MBP/Fe had ameliorative effects, restoring hemoglobin (HGB), red blood cell (RBC), hematocrit (HCT), and serum iron (SI) levels as well as total iron binding capacity (TIBC) and body weight gain of the IDA mice to normal levels. Compared to the inorganic (FeSO4) and organic (Gly-Fe) iron treatments, the spleen coefficient and damage to liver and spleen tissues were significantly lower in the H-MBP-Fe and MBP/Fe mixture groups, with reparative effects on jejunal tissue. Gene expression analysis of the iron transporters Dmt 1 (Divalent metal transporter 1), Fpn 1 (Ferroportin 1), and Dcytb (Duodenal cytochrome b) indicated that MBP promoted iron uptake. These findings suggest that mung bean peptide-ferrous chelate has potential as a peptide-based dietary supplement for treating iron deficiency.

Control of the Iron State in Pharmaceuticals Used for Treatment and Prevention of Iron Deficiency Using Mössbauer Spectroscopy

Various iron-containing medicaments, vitamins and dietary supplements are used or developed for treatment and prevention of the iron deficiency anemia which is very dangerous for human and may cause various disorders. From the other hand, blood losses, iron poor diet, microelements (co-factors) deficiency, metabolic failures, absorption problems, etc. can change the iron status and affect the health. These pharmaceuticals contain iron compounds in the ferrous and ferric states. It is known that ferrous salts are more suitable for the intestinal intake than ferric ones. On the other hand, pharmaceutically important ferritin analogues contain ferric hydrous oxides and appear to be effective for both injections and peroral administration. 57Fe Mössbauer spectroscopy is a unique physical technique which allows one to study various iron-containing materials including pharmaceuticals. Therefore, this technique was applied to study iron-containing pharmaceuticals for the analysis of the iron state, identification of ferric and ferrous compounds, revealing some structural peculiarities and for detection of aging processes in relation to the iron compounds. This review considers the main results of a long experience in the study of iron-containing pharmaceuticals by Mössbauer spectroscopy with critical analysis that may be useful for pharmacists, biochemists, biophysicists, and physicians.

Analysis of the iron states in iron-containing pharmaceutical products using Mössbauer spectroscopy

Iron-containing pharmaceuticals, namely: (i) PreNatal with ferrous fumarate, (ii) Tardyferon® with ferrous sulfate, (iii) Fenules with water free ferrous sulfate, (iv) Iron Complex with iron glycinate, citrate, (v) Gentle Iron, (vi) Hema-Plex® and (vii) Iron Bisglycinate with iron (ferrous) bisglycinate chelate (iron compounds are given as declared by the manufactures) were studied by 57Fe Mössbauer spectroscopy with X-ray diffraction and magnetization measurements for analysis of the iron state. The obtained results demonstrate that the iron compound announced by the manufacturer in each pharmaceutical is not homogeneous and exists as some modifications of this compound or results of its transformation/oxidation probably due to its instability. The presence of ferrous and ferric compounds is observed, and the relative ferric iron fractions are roughly determined for each pharmaceutical product. This analysis clearly shows the differences between the iron compounds proclaimed by the manufacturers and those obtained by Mössbauer spectroscopy. That justifies as to why this technique should be used for the control and analysis of the iron-containing pharmaceuticals.

Approaches to Address the Anemia Challenge

Anemia is a multifactorial condition; approaches to address it must recognize that the causal factors represent an ecology consisting of internal (biology, genetics, and health) and external (social/behavioral/demographic and physical) environments. In this paper, we present an approach for selecting interventions, followed by a description of key issues related to the multiple available interventions for prevention and reduction of anemia. We address interventions for anemia using the following 2 main categories: 1) those that address nutrients alone, and, 2) those that address nonnutritional causes of anemia. The emphasis will be on interventions of public health relevance, but we also consider the clinical context. We also focus on interventions at different stages of the life course, with a particular focus on women of reproductive age and preschool-age children, and present evidence on various factors to consider when selecting an intervention-inflammation, genetic mutations, nutrient delivery, bioavailability, and safety. Each section on an intervention domain concludes with a brief discussion of key research areas.

A Step for the Valorization of Spent Yeast through Production of Iron–Peptide Complexes—A Process Optimization Study

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.

Low-dose ferrous bisglycinate chelate supplementation in chronic kidney disease and hemodialysis patients

BACKGROUND

Provision of parenteral or oral iron supplementation can restore iron stores and maintain stable hemoglobin levels in chronic kidney disease (CKD) and hemodialysis (HD) patients. The route for oral or intravenous (IV) administration of iron depends on the acuity of anemia, costs, and patient tolerance. IV iron can restore iron stores rapidly but also carries higher risks for allergy and infection. Oral iron supplementation is limited by high gastrointestinal adverse effects.

METHODS

We conducted an open-label trial to study the efficiency of a film-coated iron supplementation tablet, which contains ferrous bisglycinate chelate, vitamin C, and folic acid, in CKD stage 3b to 4 and HD patients.

RESULTS

Twenty-seven HD patients and 20 CKD patients participated this study. After a 16-week intervention, low-dose ferrous bisglycinate chelate improved serum iron concentration (67.8 vs 87.2 mg/dL, p = 0.04) and transferrin saturation (24.7% vs 31.3%, p = 0.03) in stage 3 to 4 CKD patients, restored iron loss, and maintained stable hemoglobin levels in HD patients. No GI upset events were reported.

CONCLUSION

Ferrous bisglycinate chelate is a well-tolerated oral iron supplementation for CKD and HD patients.

Ferrous Bisglycinate Supplementation Modulates Intestinal Antioxidant Capacity via the AMPK/FOXO Pathway and Reconstitutes Gut Microbiota and Bile Acid Profiles in Pigs

Multi-omics were applied to compare the risks and benefits of ferrous sulfate (FeSO₄) and ferrous bisglycinate (FebisGly) in pigs in the current study. The FebisGly group showed reduced triglyceride (TG) and triglyceride/total cholesterol (TG/CHOL) values in the serum and reduced malondialdehyde (MDA) and increased glutathione (GSH) levels in the duodenum. Transcriptome analysis revealed that differentially expressed genes in the duodenum were enriched in oxidative phosphorylation, AMPK, and FOXO signaling pathways between FeSO₄ and FebisGly groups. AMPK phosphorylation and FOXO3 protein expressions were significantly increased in the FebisGly group. Bacterial 16S rRNA gene sequence analysis revealed significantly reduced alpha diversity in the FeSO₄ group and increased Firmicutes, reduced Bacteroidetes, and Proteobacteria abundances in the FebisGly group. Targeted metabolome revealed notably increased lithocholic acid (LCA), glycolithocholic acid (GLCA), hyodeoxycholic acid (HDCA), ursodeoxycholic acid (UDCA), and glycoursodeoxycholic acid (GUDCA) in the FebisGly group. RDA analysis indicated that Fusobacteria was positively correlated with TG and TG/high-density lipoprotein in the FeSO₄ group while Christensenellaceae_R-7_group, Ruminococcaceae_UCG-002, and Ruminococcaceae_UCG-005 were positively correlated with UDCA and GLCA in the FebisGly group. According to the current study, FebisGly improves serum lipid metabolism, modulates intestinal antioxidant capacity via the AMPK/FOXO pathway, and reconstitutes gut microbiota and bile acid profiles in pigs.

New Insights into Iron Deficiency Anemia in Children: A Practical Review

Iron deficiency anemia (IDA) is the most frequent hematological disorder in children, with an incidence in industrialized countries of 20.1% between 0 and 4 years of age and 5.9% between 5 and 14 years (39 and 48.1% in developing countries). Although IDA has been recognized for a long time, there are still uncovered issues and room for improving the management of this condition. New frontiers regarding its diagnosis and therapeutic options emerge every day; recently, innovative formulations of iron have been launched, both for oral and parenteral administration, with the aim of offering treatment schedules with higher efficacy and lower toxicity. As a matter of fact, glycinate and liposomal preparations, while maintaining a satisfying efficacy profile, have significantly fewer side effects, in comparison to the traditional elemental iron salts; parenteral iron, usually considered a second-choice therapy reserved to selected cases, may evolve further, as a consequence of the production of molecules with an interesting clinical profile such as ferrocarboxymaltose, which is already available for adolescents aged >14 years. The present article reports the clinically relevant latest insights regarding IDA in children and offers a practical guide to help pediatricians, particularly to choose the most appropriate prevention and therapy strategies.

Refining Treatment Strategies for Iron Deficient Athletes

Iron deficiency (ID) is a prevailing nutritional concern amongst the athletic population due to the increased iron demands of this group. Athletes' ability to replenish taxed iron stores is challenging due to the low bioavailability of dietary sources, and the interaction between exercise and hepcidin, the primary iron-regulatory hormone. To date, copious research has explored the link between exercise and iron regulation, with a more recent focus on optimising iron treatment applications. Currently, oral iron supplementation is typically the first avenue of iron replacement therapy beyond nutritional intervention, for treatment of ID athletes. However, many athletes encounter associated gastrointestinal side-effects which can deter them from fulfilling a full-term oral iron treatment plan, generally resulting in sub-optimal treatment efficacy. Consequently, various strategies (e.g. dosage, composition, timing) of oral iron supplementation have been investigated with the goal of increasing fractional iron absorption, reducing gastric irritation, and ultimately improving the efficacy of oral iron therapy. This review explores the various treatment strategies pertinent to athletes and concludes a contemporary strategy of oral iron therapy entailing morning supplementation, ideally within the 30 min following morning exercise, and in athletes experiencing gut sensitivity, consumed on alternate days or at lower doses.

Monitoring oral iron therapy in children with iron deficiency anemia: an observational, prospective, multicenter study of AIEOP patients (Associazione Italiana Emato-Oncologia Pediatrica)

Oral ferrous salts are standard treatment for children with iron deficiency anemia (IDA). The objective of our study was to monitor oral iron therapy in children, aged 3 months-12 years, with IDA. We prospectively collected clinical and hematological data of children with IDA, from 15 AIEOP (Associazione Italiana di Ematologia ed. Oncologia Pediatrica) centers. Response was measured by the increase of Hb from baseline. Of the 107 analyzed patients, 18 received ferrous gluconate/sulfate 2 mg/kg (ferrous 2), 7 ferrous gluconate/sulfate 4 mg/kg (ferrous 4), 7 ferric iron salts 2 mg/kg (ferric), 62 bis-glycinate iron 0.45 mg/kg (glycinate), and 13 liposomal iron 0.7-1.4 mg/kg (liposomal). Increase in reticulocytes was evident at 3 days, while Hb increase appeared at 2 weeks. Gain of Hb at 2 and 8 weeks revealed a higher median increase in both ferrous 2 and ferrous 4 groups. Gastro-intestinal side effects were reported in 16% (ferrous 2), 14% (ferrous 4), 6% (glycinate), and 0 (ferric and liposomal) patients. The reticulocyte counts significantly increased after 3 days from the start of oral iron supplementation. Bis-glycinate iron formulation had a good efficacy/safety profile and offers an acceptable alternative to ferrous iron preparations.

Antioxidant, immunomodulatory, oxidative stress inhibitory and iron supplementation effect of Astragalus membranaceus polysaccharide-iron (III) complex on iron-deficiency anemia mouse model

As iron supplement, the antioxidant activities of APS-iron (III) complex were comprehensively evaluated by 5-axe cobweb charts, which indicated the APS-iron (III) complex had a certain antioxidant activity and been weaker than that of APS. The results of immunological activity experiments indicated the stimulation index increased with APS-iron (III) complex concentration increase. When the concentration of the APS-iron (III) complex was 50 μg/mL, the lymphocytes proliferation increased by 35.7% compared with APS. APS-iron (III) complex also had better complement fixing activity than APS, 0.589 mg/mL of which achieved 50% complement fixing activities. Through the iron supplement experiments on iron-deficiency anemia mouse model, we found the APS-iron (III) complex faster increased hemoglobin concentration, SOD, CAT and faster decreased MDA to the normal level than Niferex and ferrous sulfate. Histological results revealed that the tissue sections were clear without obvious pathological changes and bone marrow had most hematopoietic cells from APS-iron (III) complex rat group, which also proved the APS-iron (III) complex had no significant side effects. Therefore, APS-iron (III) complex may be developed as a multifunctional iron supplement for clinical application.

Recovery from dietary iron deficiency anaemia in rats by the intake of microencapsulated ferric saccharate

This study examined the bioavailability of iron contained in microencapsulated ferric saccharate in a rat model of iron deficiency anaemia. Three groups of male Sprague-Dawley rats with induced iron deficiency anaemia were subsequently treated with a control Fe-deficient diet (2-6 mg Fe/Kg of diet) with or without the addition of 10 mg Fe/Kg of diet (in form of ferrous sulphate or microencapsulated ferric saccharate) for 2 weeks. The bioavailability of microencapsulated ferric saccharate was examined by measuring body weight gain, feed efficiency and reticulocyte parameters, and compared with the bioavailability of ferrous sulphate. Final body weight, feed efficiency, mean corpuscular volume of reticulocytes and average haemoglobin content in reticulocytes were significantly higher in anaemic rats supplemented with either microencapsulated ferric saccharate or ferrous sulphate, compared to anaemic controls. No significant differences were found between the two iron-supplemented groups. The total number of reticulocytes showed a similar trend. The results demonstrated that ingestion of microencapsulated ferric saccharate is as effective as ferrous sulphate in recovery from iron deficiency anaemia.

Lethal Gastric Mucosal Necrosis due to Administration of Oral Ferrous Bisglycinate Chelate to Suckling Piglets

The oral application of a newly developed ferrous bisglycinate paste for suckling piglets at a dose of 180 mg/kg body weight led to increased death rates in 10% (n = 10) of Swiss test pig breeding farms (n = 100). Necropsy examination of suckling piglets (n = 12), selected randomly from the test farms with increased death rates, demonstrated severe gastric mucosal ulceration and necrosis. Due to the presence of crystalline iron surface coating within the gastric lesions, the iron was considered as the toxic principle and cause of death. To demonstrate the direct toxicity of ferrous bisglycinate, the paste was administered experimentally to a litter of suckling piglets (n = 11). Different time points (24, 48 and 72 h post partum) and doses (180 mg/kg and 360 mg/kg) were investigated. The manufacturer's recommended dose of 180 mg/kg corresponded to approximately 36 mg Fe/kg and to 6.4 % of the acute lethal dose₅₀ of oral iron in rats. In all piglets the lesions were reproduced and most severe at the earliest time point (24 h post partum) and with the highest applied dose (360 mg/kg). The lesions were in accordance with those described from oral iron intoxication in man, suggesting pigs as an ideal animal model for oral iron toxicity studies.

Iron Supplements Modulate Colon Microbiota Composition and Potentiate the Protective Effects of Probiotics in Dextran Sodium Sulfate-induced Colitis

BACKGROUND

Iron is an important nutrient for both the host and colonizing bacteria. Oral iron supplementation may impact the composition of the microbiota and can be particularly damaging to patients suffering from inflammatory bowel disease (IBD). However, patients with IBD may require iron supplementation to treat their anemia.

METHODS

We fed mice with diets supplemented with ferrous sulfate at different doses (5, 50, and 500 mg of iron/kg chow) and with different iron formulations (ferrous sulfate, ferrous bisglycinate and ferric ethylenediaminetetraacetic acid [FEDTA]), and analyzed the effects on the composition of the gut microbiota by 16S ribosomal RNA gene sequencing. Using the dextran sodium sulfate (DSS)-induced colitis mouse model, we investigated the effects of iron supplementation in colitis severity, as well as the use of the probiotic Escherichia coli Nissle 1917 (EcN) in combination with iron supplementation.

RESULTS

Iron supplementation at different doses induced shifts in the gut microbial communities and inferred metabolic pathways. However, depending on the iron formulation used in the diets, iron supplementation during dextran sodium sulfate-induced colitis was either beneficial (ferrous bisglycinate) or highly detrimental (FEDTA). Finally, the beneficial effect of the probiotic EcN in the dextran sodium sulfate-induced colitis model was potentiated by oral iron supplementation with ferrous sulfate.

CONCLUSIONS

These results show that the iron formulations used to treat iron deficiency influence the gut microbiota and colitis in mice and suggest that distinct iron compounds may be of particular relevance to patients with IBD. In addition, the beneficial action of probiotics in IBD may be enhanced by oral iron supplementation.

Treatment of mild non-chemotherapy-induced iron deficiency anemia in cancer patients: comparison between oral ferrous bisglycinate chelate and ferrous sulfate

In cancer patients mild-moderate non-chemotherapy-induced iron deficiency anemia (IDA) is usually treated with oral iron salts, mostly ferrous sulfate. In this study, we compare efficacy and toxicity of oral ferrous bisglycinate chelate and ferrous sulfate in cancer patients with mild IDA. Twenty-four patients operated on for solid tumors (10 breast, 12 colorectal, 2 gastric), aged 61±10 years (range 45-75), with non-chemotherapy-induced hemoglobin (Hb) values between 10 and 12 g/dL and ferritin lower than 30 ng/mL were randomized to receive oral ferrous bisglycinate chelate, 28 mg per day for 20 days, and then 14 mg per day for 40 days (12 patients) (A group) or oral ferrous sulphate, 105 mg per day for 60 days (12 patients) (B group). Values of hemoglobin and ferritin obtained at diagnosis, 1 and 2 months from the beginning of treatment were compared. Adverse events (AEs) related to the two treatments were recorded. In the 12 patients treated with ferrous bisglycinate chelate, basal hemoglobin and ferritin values (mean±SD) were 11.6±0.8 g/dL and 16.1±8.0 ng/mL. After 2 months of treatment, they were 13.0±1.4 g/dL and 33.8±22.0 ng/mL, respectively (P=0.0003 and P=0.020). In the group treated with ferrous sulphate, hemoglobin and ferritin mean values were 11.3±0.6 g/dL and 19.0±6.4 ng/mL basally, and 12.7±0.70 g/dL and 40.8±28.1 ng/mL (P<0.0001 and P=0.017) after 2 months of treatment. AEs occurred in six cases. In all these six cases, two (17%) treated with ferrous bisglycinate chelate and four (33%) with ferrous sulphate, toxicity was grade 1. In conclusion, these data suggest that ferrous bisglycinate chelate has similar efficacy and likely lower GI toxicity than ferrous sulphate given at the conventional dose of 105 mg per day for the same time.

A multi-micronutrient beverage enhances the vitamin A and zinc status of Nigerian primary schoolchildren

Schoolchildren in Nigeria are rarely targeted by micronutrient interventions. We completed a 6-mo, double-blind, placebo-controlled trial to determine the effects of a multi-micronutrient beverage on biochemical and anthropometric indicators of nutritional status among schoolchildren participating in a pilot school feeding program in Nasarawa State, Nigeria. Children received 1 of 2 interventions 5 d/wk during school hours: 1) 250 mL/d of a multi-micronutrient beverage that included vitamin A, iron, and zinc (micronutrient); or 2) an isoenergetic control beverage (control). At baseline, 566 children 5-13 y old were randomized to groups (micronutrient: n = 288; control: n = 278). Height, weight, hemoglobin, and serum concentrations of C-reactive protein, ferritin, retinol, and zinc were measured at baseline and at the end of the study. A total of 270 children in the micronutrient group and 264 children in the control group completed the study. Self-reports of vomiting increased in both groups at 6 mo; however, the prevalence tended to be greater in the micronutrient group (21%) compared to the control group (14%) (P = 0.06). Biochemical changes were greater in the micronutrient group compared to control for serum retinol (0.10 ± 0.02 μmol/L vs. 0.02 ± 0.02 μmol/L; P = 0.016) and zinc (1.0 ± 0.2 μmol/L vs. 0.6 ± 0.2 μmol/L; P = 0.031). The intervention did not significantly affect hemoglobin or serum ferritin concentrations. The cost effectiveness of the intervention needs to be further evaluated, as does the efficacy of the beverage on anemia and indicators of iron status.

Preparation and pH stability of ferrous glycinate liposomes

Ferrous glycinate liposomes were prepared by reverse phase evaporation method. The effects of cholesterol, Tween 80, ferrous glycinate concentration, hydrating medium, pH of hydrating medium, and sonication strength on the encapsulation efficiency of liposomes were investigated. Encapsulation efficiency was significantly influenced by the different technique parameters. Ferrous glycinate liposomes might be obtained with high encapsulation efficiency of 84.80% under the conditions of optimized technique parameters. The zeta potential and average particle size of liposomes in the hydrating medium of pH 7.0 were 9.6 mV and 559.2 nm, respectively. The release property of ferrous glycinate liposomes in vitro was investigated in simulated gastrointestinal juice. A small amount of ferrous glycinate was released from liposomes in the first 4 h in simulated gastrointestinal juice. The mean diameters of liposomes increased from 559.2 to 692.9, 677.8, and 599.3 nm after incubation in simulated gastrointestinal juice of pH 1.3, 7.5, and 7.5 in the presence of bile salts, respectively. Results showed that the stability of ferrous glycinate in strong acid environment was greatly improved by encapsulation in liposomes, which protected ferrous glycinate from disrupting the extracapsular environment by lipid bilayer. The bioavailability of ferrous glycinate, as the iron source for biological activity including hemoglobin formation, may be increased. The ferrous glycinate liposomes may be a kind of promising iron fortifier.

Determination of the iron state in ferrous iron containing vitamins and dietary supplements: Application of Mössbauer spectroscopy

Determination of the iron state in commercially manufactured iron containing vitamins and dietary supplements is important for evaluation of pharmaceuticals quality. Mössbauer (nuclear gamma-resonance) spectroscopy was used for analyzing the iron state in commercial pharmaceutical products containing ferrous fumarate (FeC(4)H(2)O(4)), ferrous sulfate (FeSO(4)), ferrous bisglycinate chelate (Ferrochel) and ferrous iron (hydrolyzed protein chelate). Mössbauer parameters and the iron states were determined for iron compounds in the studied pharmaceuticals. Various ferric and ferrous impurities were found in all of the commercial products. The quantities of ferric impurities exceeded the FDA limitation of 2% in products containing ferrous fumarate. The quantities of ferric impurities exceeded 58% and 30% in products containing ferrous bisglycinate chelate and ferrous iron (hydrolyzed protein chelate), respectively. The presence of ferrous and ferric impurities was not related to the ageing of the vitamins and dietary supplements. Two pharmaceutical products contained major iron compounds, the Mössbauer parameters of which did not correspond to the ferrous fumarate or ferrous bisglycinate chelate claimed by the manufacturer.

Mössbauer spectroscopy in biomedical research

This work discusses the main directions and results of the application of Mössbauer spectroscopy of iron containing species in biomedical research. These studies demonstrate the wide possibilities of Mössbauer spectroscopy to obtain physical parameters and information about the iron electronic structure in normal and pathological biomolecules, model compounds and pharmaceutical samples as well as about qualitative and quantitative changes of iron containing biomolecules during pathological processes or the effect of environmental factors. The results obtained may be useful for further understanding of the molecular nature of diseases and pathological processes.

Iron: deficiencies and requirements

A report from the World Health Organization estimates that 46% of the world's 5- to 14-year-old children are anemic. In addition, 48% of the world's pregnant women are anemic. A majority of these cases of anemia are due to iron deficiency. Our aim here is to review the latest data on iron regulatory mechanisms, iron sources and requirements. Human and animal studies have shown that amino acids and peptides influence iron absorption from the intestinal lumen. Inter-organ transport and uptake of nonheme iron is largely performed by the complex transferring-transferring receptor system. Moreover, the discovery of cytoplasmic iron regulatory proteins (IRPs) has provided a molecular framework from which we understand the coordination of cellular iron homeostasis in mammals. IRPs and the iron responsive elements (IREs) to which they bind allow mammals to make use of the essential properties of iron while reducing its potentially toxic effect. Physiologic iron requirements are three times higher in pregnancy than they are in menstruating women (approximately 1200 mg must be acquired from the body's iron store or from the diet by the end of pregnancy). The administration of iron supplements weekly instead of daily in humans has been proposed and is being actively investigated as a viable means of controlling iron deficiency in populations, including pregnant women.

Iron bioavailability in humans from breakfasts enriched with iron bis-glycine chelate, phytates and polyphenols

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.