scholarly journals Duodenal mucosal and plasma ascorbate levels of patients with iron deficiency

2004 ◽  
Vol 23 (3) ◽  
pp. 279-283
Author(s):  
Bisera Atanasova ◽  
Robert Simpson ◽  
Andy Li ◽  
Kamen Tzatchev ◽  
Timothy Peters
Keyword(s):  
Ascorbic Acid ◽  
Iron Deficiency ◽  
Brush Border ◽  
Iron Absorption ◽  
Reductase Activity ◽  
Iron Status ◽  
Normal Subjects ◽  
Dietary Iron ◽  
Metaphosphoric Acid ◽  
Plasma Ascorbate

Iron is a vital element for almost all living organisms. In mammals iron is taken by the intestinal epithelium, primarily in the duodenum. The initial step of absorption involves the reduction of ferric to ferrous iron both in gastric lumen and at the brush-border apical membrane. Reductase activity is increased by factors physiologically stimulating iron absorption, such as iron deficiency and chronic hypoxia. Ascorbic acid (Vitamin C) has long been known to enhance absorption of dietary iron in humans as shown by several nutritional/dietetic studies. This effect has been ascribed to lumenal reduction and solubilization of iron. Recent molecular cloning of the mammalian duodenal brush-border reductase activity has provided evidence that ascorbate may play an intracellular role in determining iron absorption rates. Previously, ascorbate concentrations have been determined in duodenum, but only in normal subjects and there is no evidence on how duodenal ascorbate alters in relation to intestinal iron absorption. The aim of this study is to examine mucosal and plasma levels of ascorbate and dehydroascorbate in normal subjects and patients with iron deficiency that is known to be a stimulator for iron absorption. Duodenal biopsies were homogenized in 5% metaphosphoric acid using single burst homogeniser. Tissue and plasma ascorbate levels were assayed by ferrozine spectrophotometric method. Blood was taken from each subject to assess the iron status. The analyses of human samples revealed increased duodenal (p <0.001, n = 20) and plasma (p <0.001, n = 6) ascorbate levels in patients with iron deficiency. These findings support an important intracellular role of ascorbic acid in human dietary iron absorption.

scholarly journals Low Phytate Peas (Pisum sativum L.) Improve Iron Status, Gut Microbiome, and Brush Border Membrane Functionality In Vivo (Gallus gallus)

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2563 ◽  
Author(s):  
Tom Warkentin ◽  
Nikolai Kolba ◽  
Elad Tako
Keyword(s):  
Iron Deficiency ◽  
Gut Microbiota ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Iron Status ◽  
Gallus Gallus ◽  
Intestinal Microbiome ◽  
Physiological Status ◽  
Dietary Iron

The inclusion of pulses in traditional wheat-based food products is increasing as the food industry and consumers are recognizing the nutritional benefits due to the high protein, antioxidant activity, and good source of dietary fiber of pulses. Iron deficiency is a significant global health challenge, affecting approximately 30% of the world’s population. Dietary iron deficiency is the foremost cause of anemia, a condition that harms cognitive development and increases maternal and infant mortality. This study intended to demonstrate the potential efficacy of low-phytate biofortified pea varieties on dietary iron (Fe) bioavailability, as well as on intestinal microbiome, energetic status, and brush border membrane (BBM) functionality in vivo (Gallus gallus). We hypothesized that the low-phytate biofortified peas would significantly improve Fe bioavailability, BBM functionality, and the prevalence of beneficial bacterial populations. A six-week efficacy feeding (n = 12) was conducted to compare four low-phytate biofortified pea diets with control pea diet (CDC Bronco), as well as a no-pea diet. During the feeding trial, hemoglobin (Hb), body-Hb Fe, feed intake, and body weight were monitored. Upon the completion of the study, hepatic Fe and ferritin, pectoral glycogen, duodenal gene expression, and cecum bacterial population analyses were conducted. The results indicated that certain low-phytate pea varieties provided greater Fe bioavailability and moderately improved Fe status, while they also had significant effects on gut microbiota and duodenal brush border membrane functionality. Our findings provide further evidence that the low-phytate pea varieties appear to improve Fe physiological status and gut microbiota in vivo, and they highlight the likelihood that this strategy can further improve the efficacy and safety of the crop biofortification and mineral bioavailability approach.

Dietary and Physiological Factors That Affect the Absorption and Bioavailability of Iron

2005 ◽  
Vol 75 (6) ◽  
pp. 375-384 ◽  
Author(s):  
Janet R. Hunt
Keyword(s):  
Iron Deficiency ◽  
Molecular Mechanisms ◽  
Iron Absorption ◽  
Iron Status ◽  
Work Capacity ◽  
Iron Bioavailability ◽  
Human Studies ◽  
Dietary Iron ◽  
Iron Availability ◽  
Blood Indices

Iron deficiency, a global health problem, impairs reproductive performance, cognitive development, and work capacity. One proposed strategy to address this problem is the improvement of dietary iron bioavailability. Knowledge of the molecular mechanisms of iron absorption is growing rapidly, with identification of mucosal iron transport and regulatory proteins. Both body iron status and dietary characteristics substantially influence iron absorption, with minimal interaction between these two factors. Iron availability can be regarded mainly as a characteristic of the diet, but comparisons between human studies of iron availability for absorption require normalization for the iron status of the subjects. The dietary characteristics that enhance or inhibit iron absorption from foods have been sensitively and quantitatively determined in human studies employing iron isotopes. People with low iron status can substantially increase their iron absorption from diets with moderate to high availability. But while iron supplementation and fortification trials can effectively increase blood indices of iron status, improvements in dietary availability alone have had minimal influence on such indices within several weeks or months. Plentiful, varied diets are the ultimate resolution to iron deficiency. Without these, more modest food-based approaches to human iron deficiency likely will need to be augmented by dietary iron fortification.

Maturation, iron deficiency, and ligands in enteric radioiron transport in vitro

1963 ◽  
Vol 204 (1) ◽  
pp. 171-175 ◽  
Author(s):  
W. S. Ruliffson ◽  
J. M. Hopping
Keyword(s):  
Ascorbic Acid ◽  
Iron Deficiency ◽  
Iron Absorption ◽  
Deficiency Anemia ◽  
Anaerobic Incubation ◽  
Reverse Effect ◽  
Factors Affecting ◽  
Everted Gut Sac

The effects in rats, of age, iron-deficiency anemia, and ascorbic acid, citrate, fluoride, and ethylenediaminetetraacetate (EDTA) on enteric radioiron transport were studied in vitro by an everted gut-sac technique. Sacs from young animals transported more than those from older ones. Proximal jejunal sacs from anemic animals transported more than similar sacs from nonanemic rats, but the reverse effect appeared in sacs formed from proximal duodenum. When added to media containing ascorbic acid or citrate, fluoride depressed transport as did anaerobic incubation in the presence of ascorbic acid. Anaerobic incubation in the presence of EDTA appeared to permit elevated transport. Ascorbic acid, citrate, and EDTA all enhanced the level of Fe59 appearing in serosal media. These results appear to agree with previously established in vivo phenomena and tend to validate the in vitro method as one of promise for further studies of factors affecting iron absorption and of the mechanism of iron absorption.

Iron Amino Acid Chelates

2004 ◽  
Vol 74 (6) ◽  
pp. 435-443 ◽  
Author(s):  
Hertrampf ◽  
Olivares
Keyword(s):  
Amino Acid ◽  
Iron Deficiency ◽  
Iron Deficiency Anemia ◽  
Ferrous Sulfate ◽  
Iron Absorption ◽  
Iron Status ◽  
Deficiency Anemia ◽  
Efficacy Trials ◽  
Food Matrices ◽  
The Cost

Iron amino acid chelates, such as iron glycinate chelates, have been developed to be used as food fortificants and therapeutic agents in the prevention and treatment of iron deficiency anemia. Ferrous bis-glycine chelate (FeBC), ferric tris-glycine chelate, ferric glycinate, and ferrous bis-glycinate hydrochloride are available commercially. FeBC is the most studied and used form. Iron absorption from FeBC is affected by enhancers and inhibitors of iron absorption, but to a lesser extent than ferrous sulfate. Its absorption is regulated by iron stores. FeBC is better absorbed from milk, wheat, whole maize flour, and precooked corn flour than is ferrous sulfate. Supplementation trials have demonstrated that FeBC is efficacious in treating iron deficiency anemia. Consumption of FeBC-fortified liquid milk, dairy products, wheat rolls, and multi-nutrient beverages is associated with an improvement of iron status. The main limitations to the widespread use of FeBC in national fortification programs are the cost and the potential for promoting organoleptic changes in some food matrices. Additional research is required to establish the bioavailability of FeBC in different food matrices. Other amino acid chelates should also be evaluated. Finally there is an urgent need for more rigorous efficacy trials designed to define the relative merits of amino acid chelates when compared with bioavailable iron salts such as ferrous sulfate and ferrous fumarate and to determine appropriate fortification levels

scholarly journals Ferroportin-Hepcidin Axis in Prepubertal Obese Children with Sufficient Daily Iron Intake

2018 ◽  
Vol 15 (10) ◽  
pp. 2156 ◽  
Author(s):  
Joanna Gajewska ◽  
Jadwiga Ambroszkiewicz ◽  
Witold Klemarczyk ◽  
Ewa Głąb-Jabłońska ◽  
Halina Weker ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Iron Status ◽  
Hematological Parameters ◽  
Daily Intake ◽  
Normal Weight ◽  
Deficiency Anemia ◽  
Dietary Iron ◽  
Iron Intake ◽  
Obese Children ◽  
Iron Concentrations

Iron metabolism may be disrupted in obesity, therefore, the present study assessed the iron status, especially ferroportin and hepcidin concentrations, as well as associations between the ferroportin-hepcidin axis and other iron markers in prepubertal obese children. The following were determined: serum ferroportin, hepcidin, ferritin, soluble transferrin receptor (sTfR), iron concentrations and values of hematological parameters as well as the daily dietary intake in 40 obese and 40 normal-weight children. The ferroportin/hepcidin and ferritin/hepcidin ratios were almost two-fold lower in obese children (p = 0.001; p = 0.026, respectively). Similar iron concentrations (13.2 vs. 15.2 µmol/L, p = 0.324), the sTfR/ferritin index (0.033 vs. 0.041, p = 0.384) and values of hematological parameters were found in obese and control groups, respectively. Iron daily intake in the obese children examined was consistent with recommendations. In this group, the ferroportin/hepcidin ratio positively correlated with energy intake (p = 0.012), dietary iron (p = 0.003) and vitamin B12 (p = 0.024). In the multivariate regression model an association between the ferroportin/hepcidin ratio and the sTfR/ferritin index in obese children (β = 0.399, p = 0.017) was found. These associations did not exist in the controls. The results obtained suggest that in obese children with sufficient iron intake, the altered ferroportin-hepcidin axis may occur without signs of iron deficiency or iron deficiency anemia. The role of other micronutrients, besides dietary iron, may also be considered in the iron status of these children.

scholarly journals Intestinal Mucosal Mechanisms Controlling Iron Absorption

Blood ◽  
1963 ◽  
Vol 22 (4) ◽  
pp. 406-415 ◽  
Author(s):  
MARCEL E. CONRAD ◽  
WILLIAM H. CROSBY ◽  
Betty Merrill
Keyword(s):  
Iron Deficiency ◽  
Epithelial Cells ◽  
Iron Absorption ◽  
The Body ◽  
Iron Store ◽  
Dietary Iron ◽  
Receptor System ◽  
Excess Iron ◽  
Metabolic Requirement ◽  
Iron Receptor

Abstract Radioautographic studies provide evidence to support a concept of the mechanism whereby the small intestine controls absorption of iron. Three different states of the body’s iron stores have been considered in this regard: iron excess, iron deficiency and normal iron repletion. As the columnar epithelial cells of the duodenal villi are formed they incorporate a portion of intrinsic iron from the body’s iron store, the amount depending upon the body’s requirement for new iron. It is predicated that with iron excess the iron-receptor mechanism in these cells is saturated with intrinsic iron; this then prevents the cell from accepting dietary iron. In the normal state of iron repletion the receptor mechanism remains partly unsaturated, allowing small amounts of dietary iron to enter the cell. Part of this proceeds into the body to satisfy any metabolic requirement for iron. Part is retained in the mucosal epithelial cells to complete the saturation of the iron-receptor mechanism. This bound iron is subsequently lost when the epithelial cells are sloughed at the end of their life cycle. In iron deficiency it is postulated that the receptor system is inactive or diminished so that entry of dietary iron into the body is relatively uninhibited.

Food iron absorption in idiopathic hemochromatosis

Blood ◽  
1989 ◽  
Vol 74 (6) ◽  
pp. 2187-2193 ◽  
Author(s):  
SR Lynch ◽  
BS Skikne ◽  
JD Cook
Keyword(s):  
Serum Ferritin ◽  
Iron Absorption ◽  
Iron Status ◽  
Normal Subjects ◽  
Heme Iron ◽  
Nonheme Iron ◽  
Ferritin Concentration ◽  
Normal Volunteers ◽  
Idiopathic Hemochromatosis ◽  
The Relationship

Abstract The relationship between iron status and food iron absorption was evaluated in 75 normal volunteers, 15 patients with idiopathic hemochromatosis, and 22 heterozygotes by using double extrinsic radioiron tags to label independently the nonheme and heme iron components of a hamburger meal. In normal subjects, absorption from each of these pools was inversely correlated with storage iron, as measured by the serum ferritin concentration. In patients with hemochromatosis, absorption of both forms of iron was far greater than would be predicted from the relationship between absorption and serum ferritin observed in normal volunteers. Nevertheless, there was still a modest but statistically significant reduction in absorption of nonheme iron with increasing serum ferritin. This relationship could not be demonstrated in the case of heme iron absorption. In heterozygotes, nonheme iron absorption from a hamburger meal containing no supplementary iron did not differ significantly from that observed in normal volunteers. However, when this meal was both modified to promote bioavailability and supplemented with iron, absorption of nonheme iron was significantly elevated. These studies confirm the presence of excessive nonheme iron absorption even from unfortified meals in patients with idiopathic hemochromatosis and suggest in addition that they are particularly susceptible to iron loading from diets containing a high proportion of heme iron. Impaired regulation of nonheme iron absorption was also observed in heterozygous individuals, but a statistically significant abnormality was demonstrable only when the test meal contained a large highly bioavailable iron supplement.

Is Serum Hepcidin a Useful Diagnostic Test for Iron Deficiency?

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2056-2056
Author(s):  
Sant-Rayn S Pasricha ◽  
Zoe McQuilten ◽  
Mark Westerman ◽  
Anthony Keller ◽  
Elizabeta Nemeth ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Board Of Directors ◽  
Diagnostic Test ◽  
Sensitivity And Specificity ◽  
Whole Blood ◽  
Blood Donation ◽  
Iron Status ◽  
Life Sciences ◽  
Normal Subjects ◽  
Advisory Committees

Abstract Abstract 2056 Introduction: Iron deficiency remains the commonest blood disorder worldwide. Hepcidin is a key regulator of iron homeostasis. In iron depletion, decreased hepcidin facilitates increased iron absorption and recycling. Hepcidin is detectable in whole blood, serum & urine, and although assays have been developed, the utility and clinically appropriate cutoffs for diagnosis of iron deficiency remain to be established. Blood donors are at particular risk of iron deficiency, yet early diagnosis remains challenging in this setting; thus donors are an ideal population in which to evaluate a new diagnostic test of iron deficiency. We evaluated hepcidin as a diagnostic test of iron deficiency in female blood donors. Methods: Subjects: Premenopausal, non-anemic females accepted for whole blood donation by the Australian Red Cross Blood Service, not taking iron supplements and with no history of hemochromatosis. Iron status assessment: Serum ferritin (chemiluminescence), soluble transferrin receptor (sTfR) (immunoturbidometry) and serum hepcidin (competitive ELISA). Analysis: Diagnostic utility of hepcidin, compared with ‘gold standards’ ferritin, sTfR and sTfR/log(ferritin) index, was evaluated by Area under Receiver Operating Characteristic curves (AUCROC). Potential hepcidin cutoffs were identified, and their sensitivities and specificities evaluated. Results: We recruited 261 donors: 22.6% had ferritin<15ng/mL, 10.3% had sTfR>4.4mg/mL, and 20.3% had sTfR/log(ferritin) index>3.2. The 95% range of hepcidin values was <5.4-175.0ng/mL (overall); 9.3–203.0ng/mL (if ferritin≥15ng/mL); and 8.1–198.5ng/mL (if sTfR/log(ferritin)index≤3.2). By linear regression, log(hepcidin) was associated with log(ferritin) (coefficient +1.08, P<0.001); log(sTfR) (coefficient -2.02, P<-0.001) and log(sTfR/ferritin index) (coefficient -1.58, P<0.001). The AUCROC for hepcidin, compared with sTfR/log(ferritin) index>3.2 was 0.89, compared with ferritin<15ng/mL was 0.87 and compared with sTfR>4.4mg/mL was 0.81. An undetectable hepcidin (<5.4ng/mL) had sensitivity and specificity of 32.2% and 99.9% respectively for identification of sTfR/log(ferritin) index>3.2; hepcidin<8.1ng/mL had sensitivity and specificity of 41.5% and 97.5% respectively, and hepcidin<20ng/mL had sensitivity and specificity 74.6% and 83.2% respectively. Conclusions: Hepcidin shows promise as a diagnostic test for iron deficiency. Further work is needed to select suitable cutoffs for this assay, however a cutoff of <8.1ng/mL seems to accurately identify normal subjects, whilst <20ng/mL offers a balance between appropriate identification of cases and normal subjects. Hepcidin may become a valuable clinical index of iron status. Rapid diagnosis of iron deficiency with point of care whole blood or urine hepcidin assays may be achievable and useful in various settings, including blood donation. Prevention of donor iron deficiency is a high priority for the Australian Red Cross Blood Service and is being addressed through a comprehensive strategy. Disclosures: Westerman: Intrinsic Life Sciences: Employment, Membership on an entity's Board of Directors or advisory committees. Nemeth:Intrinsic Life Sciences: Employment, Membership on an entity's Board of Directors or advisory committees. Ganz:Intrinsic Life Sciences: Employment, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Food iron absorption in idiopathic hemochromatosis

Blood ◽  
1989 ◽  
Vol 74 (6) ◽  
pp. 2187-2193 ◽  
Author(s):  
SR Lynch ◽  
BS Skikne ◽  
JD Cook
Keyword(s):  
Serum Ferritin ◽  
Iron Absorption ◽  
Iron Status ◽  
Normal Subjects ◽  
Heme Iron ◽  
Nonheme Iron ◽  
Ferritin Concentration ◽  
Normal Volunteers ◽  
Idiopathic Hemochromatosis ◽  
The Relationship

The relationship between iron status and food iron absorption was evaluated in 75 normal volunteers, 15 patients with idiopathic hemochromatosis, and 22 heterozygotes by using double extrinsic radioiron tags to label independently the nonheme and heme iron components of a hamburger meal. In normal subjects, absorption from each of these pools was inversely correlated with storage iron, as measured by the serum ferritin concentration. In patients with hemochromatosis, absorption of both forms of iron was far greater than would be predicted from the relationship between absorption and serum ferritin observed in normal volunteers. Nevertheless, there was still a modest but statistically significant reduction in absorption of nonheme iron with increasing serum ferritin. This relationship could not be demonstrated in the case of heme iron absorption. In heterozygotes, nonheme iron absorption from a hamburger meal containing no supplementary iron did not differ significantly from that observed in normal volunteers. However, when this meal was both modified to promote bioavailability and supplemented with iron, absorption of nonheme iron was significantly elevated. These studies confirm the presence of excessive nonheme iron absorption even from unfortified meals in patients with idiopathic hemochromatosis and suggest in addition that they are particularly susceptible to iron loading from diets containing a high proportion of heme iron. Impaired regulation of nonheme iron absorption was also observed in heterozygous individuals, but a statistically significant abnormality was demonstrable only when the test meal contained a large highly bioavailable iron supplement.

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