Low Iron Absorption Research Articles

Improvement of iron availability from phytase-treated Pisum sativum, L. flour

The effect of dephytinization, using an exogenous microbial phytase under optimal conditions (pH 5.5, 37 °C), and subsequent removal of the soaking solution after processing, on the bioavailability of iron from pea ( Pisum sativum L.) flour was studied in growing rats by examining the chemical composition of pea flours, and the digestive and metabolic utilization of the above-mentioned mineral. Soaking of the pea flour led to a considerable reduction in the content of iron (33%), whereas a lower reduction in iron content (7%), associated with a higher concentration of total phosphorus, was obtained after additional treatment with phytase, than in the soaked pea flour. The digestive utilization of iron from the raw and soaked pea flours by growing rats was negligible, but increased significantly as a result of phytase treatment. The low iron absorption obtained for the former two dietary treatments during an experimental period of ten days was not reflected in any of the haematological indices (red blood count, haemoglobin, haematocrit) or tissues (femur, heart, kidney) studied, with the exception of the sternum.

Tratamiento de la hemocromatosis hereditaria tipo 1 con magnesio oral

An essential step in the pathogenesis of hereditary hemochromatosis seems to be the increased expression of a duodenal divalent cation transporter (DMT1) responsible for absorption of non-heminic iron2+. The objective of the present study was to ascertain whether the competitive blockade of DMT1 by the administration of high doses of oral Mg2+ reduces iron absorption in patients homozygous for the C282Y mutation.Iron absorption was evaluated by a low dose iron absorption test in 15 patients before and after treatment with oral magnesium (809.6 mg every 8 hours) for two weeks.We did not observe secondary effects or significant differences in iron absorption before or after magnesium treatment (14.7 micromol/L; 95% confidence interval [CI], 9.8-19.6 vs 14.9 micromol/L; 95% CI, 8.5-21.4, P = 0.7).Treatment with oral magnesium does not reduce iron absorption in homozygous C282Y patients. This treatment can not be used in these subjects.

Degradation of phytic acid in cereal porridges improves iron absorption by human subjects

Phytic acid in cereal-based and legume-based complementary foods inhibits iron absorption. Low iron absorption from cereal porridges contributes to the high prevalence of iron deficiency in infants from developing countries. The objective was to measure the influence of phytic acid degradation on iron absorption from cereal porridges. An exogenous phytase was used to fully degrade phytic acid during the manufacture of 9 roller-dried complementary foods based on rice, wheat, maize, oat, sorghum, and a wheat-soy blend. Iron absorption from the phytate-free and native phytate porridges prepared with water or milk (wheat only) was measured in adult humans with an extrinsic-label radioiron technique. Ascorbic acid was added to some porridges. When the foods were reconstituted with water, dephytinization increased iron absorption from rice porridge from 1.73% to 5.34% (P < 0.001), from oat from 0.33% to 2.79% (P < 0.0001), from maize from 1.80% to 8.92% (P < 0.0001), from wheat from 0.99% to 11.54% (P < 0.0001), from the wheat-soy blend without ascorbic acid from 1.15% to 3.75% (P < 0.005), and from the wheat-soy blend with ascorbic acid from 2.40% to 8.46% (P < 0.005). Reconstituting wheat porridge with milk instead of water markedly decreased or completely removed the enhancing effect of dephytinization on iron absorption in the presence and absence of ascorbic acid. Dephytinization did not increase iron absorption from high-tannin sorghum porridge reconstituted with water but increased iron absorption from low-tannin sorghum porridge by approximately 2-fold (P < 0.01). Phytate degradation improves iron absorption from cereal porridges prepared with water but not with milk, except from high-tannin sorghum.

Influence of ascorbic acid on iron absorption from an iron-fortified, chocolate-flavored milk drink in Jamaican children

The influence of ascorbic acid on iron absorption from an iron-fortified, chocolate-flavored milk drink (6.3 mg total Fe per serving) was evaluated with a stable-isotope technique in 20 6-7-y-old Jamaican children. Each child received two test meals labeled with 5.6 mg 57Fe and 3.0 mg 58Fe as ferrous sulfate on 2 consecutive days. Three different doses of ascorbic acid (0, 25, and 50 mg per 25-g serving) were evaluated in two separate studies by using a crossover design. Iron isotope ratios were measured by negative thermal ionization mass spectrometry. In the first study, iron absorption was significantly greater (P < 0.0001) after the addition of 25 mg ascorbic acid: geometric mean iron absorption was 1.6% (range: 0.9-4.2%) and 5.1% (2.2-17.3%) for the test meals containing 0 and 25 mg ascorbic acid, respectively. In the second study, a significant difference (P < 0.05) in iron absorption was observed when the ascorbic acid content was increased from 25 to 50 mg: geometric mean iron absorption was 5.4% (range: 2.7-10.8%) compared with 7.7% (range: 4.7-16.5%), respectively. The chocolate drink contained relatively high amounts of polyphenolic compounds, phytic acid, and calcium, all well-known inhibitors of iron absorption. The low iron absorption without added ascorbic acid shows that chocolate milk is a poor vehicle for iron fortification unless sufficient amounts of an iron-absorption enhancer are added. Regular consumption of iron-fortified chocolate milk drinks containing added ascorbic acid could have a positive effect on iron nutrition in population groups vulnerable to iron deficiency.

Bioavailability to rats of iron from fortified grain amaranth

In this study, fortified and unfortified grain amaranth seed flour diets and a FeSO4-fortified casein diet (used as a control) were evaluated for their iron (Fe) bioavailability. NaFeEDTA, ferrous fumarate, and FeSO4-fortified grain amaranth were fed to growing Sprague-Dawley weaning male rats. Iron intake, hemoglobin iron (HbFe) gain, Fe availability, total iron binding capacity (TIBC), serum iron, non-haem liver iron and red bloodcell volume (RBV) were determined, and the values were compared with those of the FeSO4-fortified casein diet control. Ferrous fumarate fortified diets gave consistently high values for all these parameters, compared with consistently low values for the amaranth diet without iron fortification. Relative biological values (RBVs) were 0.40, 1.55, 1.75, 1.67 and 1.00 for animals fed on an unfortified amaranth diet, and diets fortified with NaFeEDTA, ferrous fumarate, FeSO4 and casein fortified with FeSO4, respectively. Using FeSO4-fortified casein as control, ferrous fumarate gave a superior RBVs (1.75 vs. 1.00). The RBVs, of the unfortified cereal diets were 40% that of the control, perhaps suggesting low iron absorption from the amaranth cereal. Based on the results of this study, amaranth cereal can be considered an idea food vehicle for iron fortification. The iron fortification of choice is ferrous fumarate.

ABSORPTION OF LOW AND THERAPEUTIC DOSES OF FERRIC MALTOL, A NOVEL FERRIC IRON COMPOUND, IN IRON DEFICIENT SUBJECTS USING A SINGLE DOSE IRON ABSORPTION TEST

Ferric maltol is a novel ferric iron compound with potential use as an oral therapy for iron deficiency anaemia. Using a single, low dose iron absorption test we compared absorption of ferric maltol with absorption of ferrous sulphate in 21 iron deficient subjects. Absorption of 10 mg of ferric maltol as either aqueous solution or a single tablet compared favourably with that of an equivalent dose of ferrous sulphate. At a higher, more therapeutic dose of 60 mg elemental iron as tablets, absorption of ferric maltol appeared to be both more rapid and total absorption greater, than that seen with ferrous sulphate. We conclude that iron from ferric maltol, both at low dose and higher, more therapeutic doses, is at least as well absorbed as from ferrous sulphate. Ferric maltol is the first ferric iron formulation to be absorbed to a degree equivalent to that of ferrous iron salts and may represent a viable form of administration for ferric iron in the treatment of iron deficiency anaemia.

Iron absorption in the iron-deficient rat

Iron absorption in the iron-deficient rat was compared with that in the normal rat to better understand the regulation of this dynamic process. It was found that: Iron uptake by the iron-deficient intestinal mucosa was prolonged as a result of slower gastric release, particularly when larger doses of iron were employed. The increased mucosal uptake of ionized iron was not the result of increased adsorption, but instead appeared related to a metabolically active uptake process, whereas the increased mucosal uptake of transferrin iron was associated with increased numbers of mucosal cell membrane transferrin receptors. Mucosal ferritin acted as an iron storage protein, but its iron uptake did not explain the lower iron absorption in the normal rat. Iron loading the mucosal cell (by presenting a large iron dose to the intestinal lumen) decreased absorption for 3 to 4 days. Iron loading of the mucosal cell from circulating plasma transferrin was proportionate to the plasma iron concentration. Mucosal iron content was the composite of iron loading from the lumen and loading from plasma transferrin versus release of iron into the body. These studies imply that an enhanced uptake-throughout mechanism causes the increased iron absorption in the iron-deficient rat. Results were consistent with the existence of a regulating mechanism for iron absorption that responds to change in mucosal cell iron, which is best reflected by mucosal ferritin.

Prevention of Iron Deficiency by Milk Fortification

A large proportion of the milk consumed by infants in Chile is distributed by a National Food Supplementary Program. Efforts to prevent iron deficiency by milk fortification started several years ago. Initially a field study involving the simple addition of ferrous sulfate to a low-fat powdered milk was only partially successful due to the relatively low iron absorption from this product. Following the observation that the enrichment of milk with ascorbic acid markedly improved iron bioavailability, a new fortified formula was developed and has been tested in the field since 1976. This is powdered full-fat milk, biologically acidified and fortified with 15 mg Fe, as ferrous sulfate, and 100 mg ascorbic acid per 100 g powder. In a pilot study, 276 infants spontaneously weaned before 3 months of age received the fortified milk, and 278 infants receiving unfortified milk served as controls. At the end of the study (15 months of age) anemia (Hb less than 11 g/dl) was present in 25.7% of unfortified infants compared with only 2.5% in those fortified. Saturation of Transferrin less than 9% was present in 33.8% and serum ferritin less than 10 micrograms/l in 39.1% of the nonfortified infants. The figures for the fortified group were 7% and 8.5% respectively. Acceptance of the fortified formula was good. Following these observations, and as a previous step to the use of the fortified milk in the national program, the formula was tested in 7 National Health Service inner city community clinics under regular milk distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of brain Metallothionein labelled with59iron in anemic rats∗

Patients with neurotoxic and psychoanemic syndromes suffer from anemia and low iron absorption, probably the first as the result of high liposolubility of certain toxics as organic solvents, DDT, and other xenobiotics. Other syndromes have unknown ethiology, not only iron deficiency but also overload as haemochromatosis. Forty‐eight hours after intracerebroventricular administration of 2 μCi 59Fe into both lateral ventricles of ferropenic posthaemorrhagic male Wistar rats, the animals were killed and brains homogenized, sonicated, centrifuged, heated up to 85°C/5min and purified with Sephadex G‐150. Two peaks of proteins of high and low relative molecular mass are eluted, the last by analogy is suggested to be Metallothionein (MT). The order of MT concentration in organs of anemic ferropenic rats is: spleen > liver > intestinal mucosa > kidney > brain, and is higher than in control animals.