Erythrocyte incorporation of iron by 56-day-old infants fed a 58Fe-labeled supplement.
In an effort to obtain information about absorption of supplemental iron by breast-fed infants during the early months of life, we determined erythrocyte incorporation of a stable iron isotope, administered to 56-d-old breast-fed infants in the form of a 58Fe-labeled vitamin-iron supplement. Infants of similar age fed a milk-based formula low in iron (approximately 4 mg/L) were also studied. The 58Fe-labeled vitamin-iron supplement was given between feedings. Fourteen days after administration of 58Fe, mean erythrocyte incorporation of the isotope was 7.8% of the dose by breast-fed infants and 4.4% of the dose by formula-fed infants. The feeding-related difference was statistically significant, probably reflecting the greater quantities of inhibitors of iron absorption in the intestines of formula-fed infants. With mean iron intake from the 58Fe-labeled vitamin-iron supplement of 7.99 mg for the breast-fed infants, erythrocyte incorporation of 7.8% of the dose corresponded to 0.62 mg, a value in the range of the estimated requirement for absorbed iron. We conclude that 2-mo-old breast-fed infants are able to absorb nutritionally significant amounts of iron from an iron supplement.
D001942:Breast Feeding; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005293:Ferritins / Q000097:blood; D005527:Food, Fortified; D006801:Humans; D007223:Infant; D007225:Infant Food; D007501:Iron / Q000008:administration & dosage / Q000097:blood*; D008297:Male; D009752:Nutritional Status
D005293:Ferritins; D007501:Iron