Bioavailability of iron glycine as a fortificant in infant foods

Abstract

The bioavailability of iron glycine added to a vegetable infant weaning food was compared with ferrous sulfate. Stable, isotopically labeled compounds (57Fe or 58Fe) were mixed into the midday meal (1.4 mg added Fe/serving) and fed to 9-mo-old infants on alternate days for 8 d. Bioavailability, expressed as a percentage of the dose consumed, was measured from isotopic enrichment of hemoglobin 14 d after the last test meal. There was no difference between iron glycine and ferrous sulfate (x+/-SEM): 9.0+/-0.7% and 9.9+/-0.8%, respectively. The effect of chelation was examined by measuring iron bioavailability of iron glycine and ferrous sulfate added to a high-phytate (310 mg/100 g) whole-grain cereal weaning food and comparing it with a lower-phytate (147 mg/100 g) vegetable food, as used in the first study. Both iron compounds had lower bioavailability from the high-phytate food, 5.2+/-0.5% for iron glycine and 3.8+/-0.9% for ferrous sulfate, than the lower-phytate food, 9.8+/-1.5% for iron glycine and 9.1+/-1.3% for ferrous sulfate. The results showed no significant difference in bioavailability between the two forms of iron when added to infant weaning foods, suggesting that the glycine complex was fully or partially dissociated in the gastrointestinal tract. It is concluded that chelation does not improve the bioavailability of iron in the presence of dietary inhibitors.

How to Ensure Adequate Iron Absorption from Iron-fortified Food

“…28 An earlier study, however, does not support this report because infants fed a whole-grain infant cereal absorbed iron to a similar extent from ferrous bisglycinate and from ferrous sulfate. 29 Its high cost, its tendency to cause unwanted color reactions, and its tendency to provoke fat oxidation in stored cereal ours, make it an unsuitable forti cation compound for many food vehicles. It does, however, appear to be a useful fortication compound for liquid milk 30 and perhaps other milkbased products.…”

“…This can be done using radioisotopes 1,28,37 or stable isotopes. 13,29,38 If the iron compound to be tested dissolves slowly or incompletely in the gastric juice, it must be intrinsically labeled with isotope before testing. It is not possible to measure iron absorption from elemental iron powders or iron phosphates using the extrinsic tag technique.…”

The Usefulness of Elemental Iron for Cereal Flour Fortification: a Sustain Task Force Report

“…Absorption depended on the solubility of the powder in dilute acid, the surface area of the iron particles, and the particle size. In subjects with relatively low iron stores, iron absorption was 2.5 to 19%, representing RBV values of 13 to 90% relative to absorption of native bread iron labeled extrinsically with 59 FeCl 3 .…”

“…These investigators irradiated food-grade carbonyl iron (BASF) in a nuclear reactor for approximately 10 days at a temperature of 100°C. The powder was left to stand for at least 500 days so as to allow for the decay of 59 Fe and other unwanted radioisotopes, after which time the 55 Fe-labeled carbonyl iron was added to 60%-extraction wheat our and baked into bread rolls. One, two, and three mg of carbonyl iron were added to each 40 g roll representing forti cation levels of 2.5, 5.0, and 7.5 mg/ 100 g our.…”

Tratamento da anemia ferropriva com ferro quelato glicinato e crescimento de crianças na primeira infância

“…Atualmente, novos compostos com ferro são utilizados na terapêutica da anemia ferropriva, visando melhorar a tolerabilidade e minimizar os efeitos indesejáveis com o uso do medicamento. Dentro desta perspectiva, um crescente número de estudos foi publicado considerando as propriedades do ferro quelato no tratamento da carência de ferro, sob a forma de medicamento (tabletes, soluções), como também para fortificação de alimentos 11,12 , e entre as principais vantagens descritas estão a menor toxicidade e a melhor tolerabilidade, se comparado a outros sais de ferro 13,14 . Assim, diante da alta prevalência de anemia na primeira infância e de sua repercussão negativa, desenvolveu-se este estudo para avaliar a resposta à suplementação medicamentosa com dose diária de ferro quelato glicinato, e seu impacto sobre o crescimento linear em crianças anêmicas de creches municipais.…”