Relative Bioavailability Of Iron Research Articles

Ejiao peptide-iron chelates regulate the metabolism of iron deficiency anemia mice and improve the bioavailability of iron

Colla Corii Asini (Ejiao) peptide-iron (EPI) chelates formed during digestion have been revealed as potential hematopoietic components. However, it remains unclear how EPI regulates endogenous metabolism in vivo. Iron deficiency anemia (IDA) mice were gavaged with EPI chelates in a gradient dosage, while Ejiao hydrolysate-iron (EJI) chelates and FeSO4 were used as positive controls. The effect of EPI on hematopoietic recovery was evaluated. For the plasma untargeted metabolomic analysis, liquid chromatography-tandem mass spectrometry (LC-MS/MS) were applied to identify metabolites in the samples. EPI significantly increased the levels of hemogram in IDA mice in a dose-dependent manner. The relative iron bioavailability in EPI was 123.45% of that in FeSO4in vivo. After high dose of EPI (EPI-H) supplementation, the levels of 22 potential metabolic markers in the IDA group returned to normal, including sphingomyelin and arachidonic acid. EPI-H affected endogenous metabolites by regulating the metabolism of energy, lipids, and amino acids, promoted hematopoiesis, regulated metabolic pathways, and improved iron homeostasis. It’s a comprehensive nutritional intervention of IDA by EPI supplementation.

Iron Complexes with Antarctic Krill-Derived Peptides Show Superior Effectiveness to Their Original Protein-Iron Complexes in Mice with Iron Deficiency Anemia.

Antarctic krill protein-iron complex and peptide-iron complex were acquired to investigate their iron bioavailability, expression of iron-regulated genes, and in vivo antioxidant capacity. Results indicated that the Antarctic krill peptide-iron complex significantly increased the hemoglobin (Hb), serum iron (SI), and iron contents in the liver and spleen in iron-deficiency anemia (IDA) mice (p < 0.05) compared with those of the Antarctic krill protein-iron complex. Despite the gene expressions of the divalent metal transporter 1(DMT1), the transferrin (Tf), and the transferrin receptor (TfR) being better regulated by both Antarctic krill peptide-iron complex and protein-iron complex, the relative iron bioavailability of the Antarctic krill peptide-iron complex group (152.53 ± 21.05%) was significantly higher than that of the protein-iron complex group (112.75 ± 9.60%) (p < 0.05). Moreover, Antarctic krill peptide-iron complex could enhance the antioxidant enzyme activities of superoxidase dismutase (SOD) and glutathione peroxidase (GSH-Px), reduce the malondialdehyde (MDA) level in IDA mice compared with the protein-iron complex, and reduce the cell damage caused by IDA. Therefore, these results indicated that Antarctic krill peptide-iron complex could be used as a highly efficient and multifunctional iron supplement.

Iron Bioavailability from Multiple Biofortified Foods Using an In Vitro Digestion, Caco-2 Assay for Optimizing a Cyclical Menu for a Randomized Efficacy Trial.

ABSTRACTBackgroundInadequate nutritional status contributes to substantial losses in human health and productivity globally. A multiple biofortified food crop trial targeting iron, zinc, and vitamin A deficiencies among young children and their breastfeeding mothers is being conducted in India.ObjectiveWe sought to determine the relative iron bioavailability from biofortified and conventional crops and crop combinations representative of a cyclical menu using crops targeted for inclusion in the feeding trial.MethodsCrops were procured from India, cooked, freeze-dried, and analyzed with an established in vitro digestion/Caco-2 iron bioavailability assay using a fixed sample weight. Crop proportions representative of meals planned for the human study were determined and combined such that samples included either all biofortified or all control crops. Crops were analyzed as single crops (n = 4) or crop combinations (n = 7) by variety (biofortified or control) in triplicate. The primary outcome was iron uptake measured by Caco-2 ferritin production normalized to total Caco-2 protein (nanograms of ferritin/milligrams of cell protein) analyzed for effects of crop variety and crop proportion using generalized linear models.ResultsBiofortified pearl millet alone demonstrated higher iron uptake than conventional varieties (5.01 ± 1.66 vs. 2.17 ± 0.96; P = 0.036). Addition of sweet potato or sweet potato + pulse improved iron uptake for all proportions tested in control varieties and select proportions for biofortified varieties (P ≤ 0.05). Two multiple crop combinations demonstrated modestly higher iron uptake from biofortified crops.ConclusionsOptimizing total iron delivery should consider matrix effects, processing, and promoters/inhibitors of iron absorption in addition to total iron concentration. Future directions include evaluating recipes as prepared for consumption and comparison against human iron bioavailability studies.

Iron bioavailability from bouillon fortified with a novel ferric phytate compound: a stable iron isotope study in healthy women (part II)

Bouillon cubes are widely consumed and when fortified with iron could contribute in preventing iron deficiency. We report the development (part I) and evaluation (current part II) of a novel ferric phytate compound to be used as iron fortificant in condiments such as bouillon. Ferric pyrophosphate (FePP), is the compound of choice due to its high stability in foods, but has a modest absorption in humans. Our objective was to assess iron bioavailability from a novel iron fortificant consisting of ferric iron complexed with phytic acid and hydrolyzed corn protein (Fe-PA-HCP), used in bouillon with and without an inhibitory food matrix. In a randomised single blind, cross-over study, we measured iron absorption in healthy adult women (n = 22). In vitro iron bioaccessibility was assessed using a Caco-2 cell model. Iron absorption from Fe-PA-HCP was 1.5% and 4.1% in bouillon with and without inhibitory matrix, respectively. Relative iron bioavailability to FeSO4 was 2.4 times higher than from FePP in bouillon (17% vs 7%) and 5.2 times higher when consumed with the inhibitory meal (41% vs 8%). Similar results were found in vitro. Fe-PA-HCP has a higher relative bioavailability versus FePP, especially when bouillon is served with an inhibitory food matrix.

A heat-stable microparticle platform for oral micronutrient delivery.

Micronutrient deficiencies affect up to 2 billion people and are the leading cause of cognitive and physical disorders in the developing world. Food fortification is effective in treating micronutrient deficiencies; however, its global implementation has been limited by technical challenges in maintaining micronutrient stability during cooking and storage. We hypothesized that polymer-based encapsulation could address this and facilitate micronutrient absorption. We identified poly(butylmethacrylate-co-(2-dimethylaminoethyl)methacrylate-co-methylmethacrylate) (1:2:1) (BMC) as a material with proven safety, offering stability in boiling water, rapid dissolution in gastric acid, and the ability to encapsulate distinct micronutrients. We encapsulated 11 micronutrients (iron; iodine; zinc; and vitamins A, B2, niacin, biotin, folic acid, B12, C, and D) and co-encapsulated up to 4 micronutrients. Encapsulation improved micronutrient stability against heat, light, moisture, and oxidation. Rodent studies confirmed rapid micronutrient release in the stomach and intestinal absorption. Bioavailability of iron from microparticles, compared to free iron, was lower in an initial human study. An organotypic human intestinal model revealed that increased iron loading and decreased polymer content would improve absorption. Using process development approaches capable of kilogram-scale synthesis, we increased iron loading more than 30-fold. Scaled batches tested in a follow-up human study exhibited up to 89% relative iron bioavailability compared to free iron. Collectively, these studies describe a broad approach for clinical translation of a heat-stable ingestible micronutrient delivery platform with the potential to improve micronutrient deficiency in the developing world. These approaches could potentially be applied toward clinical translation of other materials, such as natural polymers, for encapsulation and oral delivery of micronutrients.

Estimation of the iron bioavailability in green vegetables using an in vitro digestion/Caco-2 cell model

It is estimated that over 30% of the global population is anaemic, half of which is due to iron deficiency. The bioavailability of iron from vegetables is low and variable, and influenced by food composition and matrix. We have therefore determined the relative bioavailability of iron in five types of green vegetable, spinach, broccoli, savoy cabbage, curly kale and green pepper, by measuring the ferritin response in a simulated digestion/Caco-2 cell model. Savoy cabbage gave the highest ferritin response and analysis of the digest showed that the iron was present in low molecular weight fractions which contained glucose, fructose, organic acids and amino acids. The addition of fructose 1,6-biphosphate to the Caco-2 cells increased iron uptake 2-fold. These results demonstrate that cabbage was the best source of bioavailable iron out of the vegetables studied and suggest that the formation of complexes with fructose derivatives contribute to increase the iron bioavailability.

Iron Bioavailability from Multiple Biofortified Foods Using an in Vitro Digestion, Caco-2 Assay for Optimizing a Cyclic Menu for a Randomized Efficacy Trial (P10-029-19)

ObjectivesA multiple biofortified food crop trial targeting iron, zinc, and vitamin A deficiencies among young children and their breastfeeding mothers is planned in India. We sought to determine iron bioavailability from biofortified and conventional crop mixes representative of planned meal components. MethodsA 24-meal menu was developed based on pearl millet, sweet potato, and lentils targeted for a feeding trial. Crops were procured from India, cooked, and freeze-dried before two rounds of an established in vitro digestion/Caco-2 iron bioavailability assay. Samples used a fixed weight adjusted for sweet potato water content. Representative crop proportions were determined using k-means clustering, combined such that samples included either all biofortified or all control crop varieties, and analyzed in triplicate. Outcomes were Caco-2 iron uptake and uptake normalized to iron per sample for fractional bioavailability. Data were analyzed with generalized linear models in SAS accounting for crop proportions and variety. ResultsAcross both experiments, biofortified pearl millet alone demonstrated higher iron uptake than conventional varieties (5.01 ± 1.66 vs. 2.17 ± 0.96 ng ferritin/mg protein, P ≤ 0.036). Addition of sweet potato to pearl millet did not change iron uptake for biofortified varieties (P ≥0.13), but increased control iron uptake for all amounts of sweet potato (P ≤ 0.006), which did not differ from biofortified varieties (P ≥ 0.08). Lentil proportion increased iron uptake (β = 4.6 ± 2.2, P = 0.009), with no effect of variety or a lentil by variety interaction (P ≥ 0.56). The overall effect estimate of biofortified vs. control was (β = 1.79 ± 0.91, P = 0.08). Iron uptake normalized to iron per sample was higher for control crops (P ≤ 0.02), and enhanced by sweet potato, while inhibited by pearl millet (both P < 0.001). ConclusionsA Caco-2 assay predicts that biofortified pearl millet alone has greater iron bioavailability than control pearl millet. The addition of sweet potato and lentils increased overall and relative iron bioavailability, while reducing differences between biofortified and control varieties. Matrix effects, processing, and promoters/inhibitors of iron absorption should be considered in addition to total iron concentration when optimizing iron bioavailability. Funding SourcesThis work was supported by HarvestPlus and the USDA. Supporting Tables, Images and/or Graphs▪

Impact of Iron-Enriched Aspergillus oryzae on Iron Bioavailability, Safety, and Gut Microbiota in Rats.

Iron deficiency is a leading global nutritional problem. Ferrous sulfate (FeSO4) is the most common iron source used for supplementation. Because of many side effects associated with its consumption, it is important to identify new forms of iron. The objectives of this study were to assess the bioavailability of iron-enriched Aspergillus oryzae, Aspiron (ASP), evaluate the toxicity of high-dose iron supplementation with ASP, and determine the ASP impact on gut microbiota in rats. In this study, we investigated iron bioavailability using the hemoglobin repletion test. Aspartate aminotransferase, alanine aminotransferase, and blood urea nitrogen levels were determined to evaluate the effect on liver and kidney functions. Protein carbonyls were measured to assess oxidative damage to proteins. Fecal samples at the end of the 14 day repletion period were used for 16S rRNA sequencing for gut microbiota analysis. The slope ratio method using a common intercept linear regression model was used to compare the bioavailability of ASP to FeSO4. Iron repletion increased hemoglobin concentrations with both ASP and FeSO4 treatments compared to the control group, except in the lowest ASP group. The slope ratio indicated that relative iron bioavailability of ASP was 60% of that of FeSO4 when hemoglobin change was compared to iron in the diet. Similar results were obtained when absolute iron intake was compared on the basis of food consumption. In comparison to the control, protein carbonyl concentrations were significantly ( p < 0.05) higher in the FeSO4 group but not with the ASP group. Supplementation with both sources of iron reduced the Enterobacteriaceae population in the gut microbiota of the rats. A higher relative abundance of bacteria from the phylum Verrucomicrobia was also observed with the highest dose of ASP. Iron-enriched A. oryzae with 60% relative bioavailability of FeSO4 did not show any signs of adverse effects after 14 days of iron supplementation. Future human studies are needed to understand the ASP detailed effect on gut microbiota.

Consumption of galacto-oligosaccharides increases iron absorption from a micronutrient powder containing ferrous fumarate and sodium iron EDTA: a stable-isotope study in Kenyan infants

Background: Whether consumption of prebiotics increases iron absorption in infants is unclear.Objective: We set out to determine whether prebiotic consumption affects iron absorption from a micronutrient powder (MNP) containing a mixture of ferrous fumarate and sodium iron EDTA (FeFum+NaFeEDTA) in Kenyan infants.Design: Infants (n = 50; aged 6-14 mo) consumed maize porridge that was fortified with an MNP containing FeFum+NaFeEDTA and 7.5 g galacto-oligosaccharides (GOSs) (Fe+GOS group, n = 22) or the same MNP without GOSs (Fe group, n = 28) each day for 3 wk. Then, on 2 consecutive days, we fed all infants isotopically labeled maize porridge and MNP test meals containing 5 mg Fe as 57FeFum+Na58FeEDTA or ferrous sulfate (54FeSO4). Iron absorption was measured as the erythrocyte incorporation of stable isotopes. Iron markers, fecal pH, and bacterial groups were assessed at baseline and 3 wk. Comparisons within and between groups were done with the use of mixed-effects models.Results: There was a significant group-by-compound interaction on iron absorption (P = 0.011). The median percentages of fractional iron absorption from FeFum+NaFeEDTA and from FeSO4 in the Fe group were 11.6% (IQR: 6.9-19.9%) and 20.3% (IQR: 14.2-25.7%), respectively, (P < 0.001) and, in the Fe+GOS group, were 18.8% (IQR: 8.3-37.5%) and 25.5% (IQR: 15.1-37.8%), respectively (P = 0.124). Between groups, iron absorption was greater from the FeFum+NaFeEDTA (P = 0.047) in the Fe+GOS group but not from the FeSO4 (P = 0.653). The relative iron bioavailability from FeFum+NaFeEDTA compared with FeSO4 was higher in the Fe+GOS group than in the Fe group (88% compared with 63%; P = 0.006). There was a significant time-by-group interaction on Bifidobacterium spp. (P = 0.008) and Lactobacillus/Pediococcus/Leuconostoc spp. (P = 0.018); Lactobacillus/Pediococcus/Leuconostoc spp. decreased in the Fe group (P = 0.013), and there was a nonsignificant trend toward higher Bifidobacterium spp. in the Fe+GOS group (P = 0.099). At 3 wk, iron absorption was negatively correlated with fecal pH (P < 0.001) and positively correlated with Lactobacillus/Pediococcus/Leuconostoc spp. (P = 0.001).Conclusion: GOS consumption by infants increased iron absorption by 62% from an MNP containing FeFum+NaFeEDTA, thereby possibly reflecting greater colonic iron absorption. This trial was registered at clinicaltrials.gov as NCT02666417.

Iron bioavailability in iron-fortified cereal foods: The contribution of in vitro studies

abstractIron deficiency anemia is the most common nutritional deficiency in humans. Not all dietary ingested iron, heme or nonheme, will be available to absorption and negative imbalance between iron requirements and absorption leads to iron deficiency and/or anemia. The recommended iron values usually are based on the genetic and on diet iron-bioavailability, which can be considered as the principal factor that change among the cultures and influences the distinct levels of recommendation among countries. Dietary changes present practical limitations due to be difficult to change food habits. The iron food fortification is considered more cost effective and economically more attractive than iron supplementation. There are many iron compounds available to be used in iron fortification. Cereals represent a target food group to iron fortification programs due to high consumption and the in vitro studies can be useful to estimate the relative iron bioavailability in large number of products in short time and with a low cost. Wheat flour baked into bread or not was the main product tested in in vitro bioavailability studies and ferrous sulfate was the principal iron compound used in the fortification studies. However, iron bioavailability from ferrous sulfate is lower than from other compounds, such FeNaEDTA or ferric pyrophosphate. The variables level of fortification, storage, level of extraction, baking and also the association or not with other chemical compound seems to influence the results obtained.

Differences in relative iron bioavailability in traditional Bangladeshi meal plans.

Iron deficiency is the most common nutrient deficiency worldwide. Large intakes of micronutrient-poor staple crops, coupled with low intakes of highly bioavailable dietary iron, are a major cause of this deficiency. To examine the concentration and relative bioavailability of iron in several models (n = 23) of traditional Bangladeshi meals (rice, lentils/dal, vegetable, and fish), as well as the effect of removal of the lentil seed coat on the nutritional quality of iron. The relative bioavailability of iron was assessed by the in vitro/Caco-2 cell culture method, iron concentration by an inductively coupled argon-plasma emission spectrometer (ICAP-ES), and phytic acid concentration by colorimetric assay. The recipes contained 75% to 85% rice, 0% to 15% dal (containing whole or dehulled lentils), 0% to 15% vegetable curry, and 0% to 8% fish. While the iron concentrations of recipes containing dehulled dal were significantly lower than those of recipes containing whole dal (p = .005), seed coat removal doubled relative iron bioavailability and increased phytic acid concentration (p < .001). The addition of fish to the meals had no significant effect on relative iron bioavailability. Iron concentration and relative iron bioavailability were correlated in the recipes containing dehulled dal (r = 0.48, p = .03), but not whole dal (r = -0.047, p = .84). The total amount of iron absorbed from traditional Bangladeshi meals is dependent upon iron concentration, and dehulling lentils removes inhibitory factors increasing iron uptake but also increases the density of phytic acid in the lentil sample. Thus, along with breeding for high iron concentration and bioavailability (i.e., biofortification), seed coat removal plus measures to lower phytic acid concentrations may be an important strategy to improve the bioavailability of iron in lentils and other pulse crops.

Relative bioavailability of iron from organic sources for weanling piglets

Alguns autores consideram os minerais de fontes orgânicas mais biodisponiveis para a nutricao de suinos quando comparados a minerais de fontes inorgânicas. Para avaliar a biodisponibilidade relativa do ferro proveniente da fonte orgânica carbo-amino-fosfo-quelato de ferro (CAFQF), foi conduzido um experimento com 126 leitoes de linhagem comercial, utilizando o sulfato de ferro (S) como padrao. O delineamento experimental foi inteiramente casualizado com sete tratamentos (dieta sem adicao de fonte especifica de ferro, dietas com 50, 100 e 150 ppm de ferro na forma de S e dietas com 50, 100 e 150 ppm de ferro na forma de CAFQF), seis repeticoes e tres animais por unidade experimental. Parâmetros de desempenho (ganho de peso medio diario – GMD, conversao alimentar – CA) e variaveis sanguineas (hemoglobina – Hb, hematrocrito – Ht, transferrina – TR, capacidade latente de ligacao do ferro – CLLF, capacidade total de ligacao do ferro – CTLF, ferro serico – FS e indice de saturacao da transferrina – IST) foram avaliados. Ao final do experimento um leitao por unidade experimental foi abatido para a retirada do figado e braco para avaliacao da concentracao de ferro por espectrometria de absorcao atomica em chama (FAAS). As fontes de ferro avaliadas apresentaram resultados semelhantes para as variaveis de interesse, mas o aumento da ingestao de ferro resultou em aumento linear nos valores de GMD, Hb, Ht, FS e IST e reducao linear nos valores de CA, TR, CLLF e CTLF. Para leitoes desmamados a biodisponibilidade do ferro proveniente do CAFQF e similar a do S.

Homogeneous Iron Phosphate Nanoparticles by Combustion of Sprays

Low-cost synthesis of iron phosphate nanostructured particles is attractive for large scale fortification of basic foods (rice, bread, etc.) as well as for Li-battery materials. This is achieved here by flame-assisted and flame spray pyrolysis (FASP and FSP) of inexpensive precursors (iron nitrate, phosphate), solvents (ethanol), and support gases (acetylene and methane). The iron phosphate powders produced here were mostly amorphous and exhibited excellent solubility in dilute acid, an indicator of relative iron bioavailability. The amorphous and crystalline fractions of such powders were determined by X-ray diffraction (XRD) and their cumulative size distribution by X-ray disk centrifuge. Fine and coarse size fractions were obtained also by sedimentation and characterized by microscopy and XRD. The coarse size fraction contained maghemite Fe(2)O(3) while the fine was amorphous iron phosphate. Furthermore, the effect of increased production rate (up to 11 g/h) on product morphology and solubility was explored. Using increased methane flow rates through the ignition/pilot flame of the FSP-burner and inexpensive powder precursors resulted in also homogeneous iron phosphate nanoparticles essentially converting the FSP to a FASP process. The powders produced by FSP at increased methane flow had excellent solubility in dilute acid as well. Such use of methane or even natural gas might be economically attractive for large scale flame-synthesis of nanoparticles.

White common beans (Phaseolus vulgaris) have higher in vitro iron bioavailability than colored seed coat varieties

The common bean is an important source of iron in developing countries and there is need to improve their iron bioavailability. This study aimed at screening 21 bean varieties (16 varieties from Uganda and 5 from Columbia) for iron bioavailability with an overall objective of modeling it with respect to key influencing factors; protein, polyphenol, phytate, bean ferritin and iron content. A Caco‐2 cell culture model was used to determine iron uptake from in vitro digested bean samples. Protein content ranged from 25.7–31.6 %; polyphenols, 0.07–0.37 mg/100g; phytates, 0.91–2.17 g/100g; iron, 128.5–154.5 μg/g; bean ferritin, 206–497 μg/g, and relative iron bioavailability (based on 100% bioavailability of ferrous sulfate) was 9.1–52.1%. The two white bean varieties had the highest bioavailability (38–52%) and were significantly different from colored seed coat varieties (9–18%). A fixed effects multiple regression model showed negative effects of polyphenols and phytates and positive effects of iron content. In conclusion, iron bioavailability in common beans is influenced by iron, polyphenol and phytate contents.Source of support: US‐AID under the Dry Grain Pulses CRSP

Evaluation of clams as a food source of iron: Total iron, heme iron, aluminum, and in vitro iron bioavailability in live and processed clams

Clams are listed on prominent healthcare websites as an excellent source of iron (Fe). However, the amount, type and bioavailability of iron in clam products are poorly understood, as is their content of environmental metals such as aluminum (Al). In this study, live Manila and processed clams were assayed for Fe, Al, and heme-iron content. Results were compared to beef. Relative iron bioavailability was assessed by an in vitro digestion/Caco-2 cell method using FeSO4 as a reference iron source. Inhibitory effects of Al and tea flavonoids on iron bioavailability were also evaluated. Mean iron content expressed as mg/reference amount (RA, 56g edible portion) ranged from 0.57 in minced clams to 17.2mg/RA in whole baby clams; Al ranged from 0.29 to 26.4mg/RA, probably reflecting grit content. Beef contained 3.0mg Fe and 0.07mg Al per RA of 85g. Heme iron was very low in clams (<0.4mg/RA) relative to beef (2.3±0.2mg/RA). One serving (56g) of live or minced clams provided less than one-third as much bioavailable iron as 9.8mg FeSO4; whereas one serving of whole baby clams provided the same amount of bioavailable iron as 9.8mg of FeSO4. Flavonoids reduced iron solubility and bioavailability; Al reduced only iron bioavailability. We conclude that live and minced clams should not be considered good sources of bioavailable iron, and the high Al content of whole baby clams raises concerns about recommending these clams as an iron source.

Comparison of a Modified Hemoglobin Regeneration Efficiency Method with a Slope-Ratio Assay in Measuring Relative Bioavailability of Cocoa Powder Iron Using Rats

The slope-ratio assay is being used as a gold standard for determining iron bioavailability in foods. We compared the modified hemoglobin (Hb) regeneration efficiency (HRE) method (Yokoi K, Konomi A, & Otagi M (2009) Br J Nutr 102: 215-220) with the slope-ratio assay for measurement of iron bioavailability. The relative bioavailability of iron in cocoa powder was measured by both methods using ferric citrate as a control (i.e., 1.00). In the slope-ratio assay, thirty-two 4-week-old male F/344N rats were depleted in iron stores for 28days, and then eight groups of four rats each were repleted for 25days using graded levels of dietary ferric citrate or the cocoa powder. The slope for the cocoa powder 1.720g Hb/L/(mg Fe/kg) was 0.99 that of ferric citrate 1.727g Hb/L/(mg Fe/kg). On the other hand, the HRE value of the cocoa powder was 0.96 that of ferric citrate, based on the previous report. The relative iron bioavailabilities measured by both methods agreed, indicating that the modified HRE method is compatible with the slope-ratio assay in measuring the bioavailability of iron in foods.

Iron bioavailability from a tropical leafy vegetable in anaemic mice

Telfairia occidentalis is a vegetable food crop that is indigenous to West Africa. The leaves and seeds are the edible parts of the plant and are used in everyday meals by incorporation into soups and stews. Previous studies have attributed improved haematological indices to the vegetable and have advocated the use of T. occidentalis in the treatment of anemia. This study investigates the ameliorative effects of T. occidentalis when compared to FeSO4 as a reference salt in anaemic mice. It also compares the bioavailability of test iron and hepatic hepcidin expression for the estimation of iron absorption in the mice. Non-haem iron was determined in the liver of mice after the experimental feeding treatments. Hepcidin mRNA expression was carried out by quantitative RT-PCR. Administration of T. occidentalis leaves led to a modest increase in haemoglobin (Hb) levels in anaemic mice that were comparable to the Hb repletion in anaemic mice given FeSO4. Hepatic iron increase in the mice given either T. occidentalis or FeSO4 led to a corresponding enhancement of hepcidin mRNA expression. Induced hepcidin mRNA expression was enhanced by the addition of ascorbic acid to the test dose of iron. Hepatic hepcidin mRNA expression was found to be responsive to increase in the relative bioavailability of iron from test diets.

Relative bioavailability of iron and folic acid from a new powdered supplement compared to a traditional tablet in pregnant women.

BackgroundDeficiencies of iron and folic acid during pregnancy can lead to adverse outcomes for the fetus, thus supplements are recommended. Adherence to current tablet-based supplements is documented to be poor. Recently a powdered form of micronutrients has been developed which may decrease side-effects and thus improve adherence. However, before testing the efficacy of the supplement as an alternate choice for supplementation during pregnancy, the bioavailability of the iron needs to be determined. Our objective was to measure the relative bioavailability of iron and folic acid from a powdered supplement that can be sprinkled on semi-solid foods or beverages versus a traditional tablet supplement in pregnant women.MethodsEighteen healthy pregnant women (24 – 32 weeks gestation) were randomized to receive the supplements in a crossover design. Following ingestion of each supplement, the changes (over baseline) in serum iron and folate over 8 hours were determined. The powdered supplement contained 30 mg of iron as micronized dispersible ferric pyrophosphate with an emulsifier coating and 600 μg folic acid; the tablet contained 27 mg iron from ferrous fumarate and 1000 μg folic acid.ResultsOverall absorption of iron from the powdered supplement was significantly lower than the tablet (p = 0.003). There was no difference in the overall absorption of folic acid between supplements. Based on the differences in the area under the curve and doses, the relative bioavailability of iron from powdered supplement was lower than from the tablet (0.22).ConclusionThe unexpected lower bioavailability of iron from the powdered supplement is contrary to previously published reports. However, since pills and capsules are known to be poorly accepted by some women during pregnancy, it is reasonable to continue to explore alternative micronutrient delivery systems and forms of iron for this purpose.Trial RegistrationClinicalTrials.gov NCT00789490

In vitro bioaccessibility of iron and zinc in fortified fruit beverages

SummaryIron and zinc bioaccessibility was estimated in the in vitro gastrointestinal digests of six different fortified fruit beverages (Fb) containing iron and/or zinc and/or skimmed milk (M). Solubility values can be used to establish trends in relative bioavailability of iron and zinc, as the first stage towards mineral bioavailability comprises solubility in the intestinal tract. FbFe, FbFeM and FbFeZnM samples showed iron bioaccessibility above 88%, differing (P &lt; 0.05) from those of FbFeZn (53%). In turn, FbZn, FbFeZn and FbZnM samples presented higher zinc bioaccessibility (above 68%), differing (P &lt; 0.05) from those of FbFeZnM (48%). The presence of milk‐derived caseinophosphopeptides (CPPs) formed during gastrointestinal digestion in dairy samples does not increase iron or zinc bioaccessibility in FbFeM or FbZnM vs. FbFe or FbZn, but it is hypothesised that the negative interacting effect of zinc upon iron bioaccessibility when co‐supplemented in these fruit beverages is overcome in the presence of CPPs, which favour iron solubility more than in the case of zinc.

Effect of Phosphate Binders on Supplemental Iron Absorption in Healthy Subjects

A single‐dose, prospective, randomized, four‐treatment, four‐period crossover study was conducted to determine the acute effect of therapeutically equivalent doses of three commonly used phosphate binders on oral iron absorption. Twenty‐three healthy subjects received 65 mg of elemental iron alone and with each phosphate binder (calcium carbonate 3000 mg, calcium acetate 2668 mg, or sevelamer HCl 2821 mg). Area under the change in plasma iron concentration‐time curve over 6 hours postdosing was measured. ANOVA was used to assess the statistical significance of differences in iron absorption among the treatments. The relative bioavailability of iron administered with each phosphate binder compared to iron administered alone was estimated. The relative iron bioavailabilities (95% confidence intervals) for the calcium carbonate, calcium acetate, and sevelamer HCl treatments were 0.81 (0.70, 0.94), 0.73 (0.63, 0.85), and 0.90 (0.78, 1.05), respectively. Thus, single doses of both calcium‐based phosphate binders significantly reduced single‐dose iron absorption, while sevelamer HCl did not.