ABSORPTION BY 1-YEAR-OLD CHILDREN OF AN IRON SUPPLEMENT GIVEN WITH COWS MILK OR JUICE

A paucity of data are available on toddlers for the evaluation of opti mal strategies of Fe supplementation. In this study, we used a two-tra cer stable isotope technique to determine Fe absorption from a 5-mg do se of stable isotopically enriched (Fe-57 or Fe-58) ferrous sulfate gi ven with cow's milk (CM) compared with the same dose given with apple juice, Ten children (age 13 +/- 1 mo, weight 10.8 +/- 1.1 kg) who had recently discontinued formula feeding and begun on CM were studied. Re d blood cell (RBC) iron incorporation of the isotope was determined 14 d after dosing with Fe-57 and Fe-58. Fe absorption was calculated bas ed on the assumption that 90% of absorbed Fe is incorporated into RBC. Absorption of Fe was significantly greater (13.7 +/- 6.4%) when given with juice than with milk (5.7 +/- 4.0%), p < 0.01 by paired t tests. Fe absorption from the dose given with juice was significantly negati vely correlated with serum ferritin (n = 9, r = -0.70, p < 0.05). Thes e results indicate that I) a small supplement of Fe is better absorbed when given with juice than with CM, and 2) a large variability in Fe absorption exists in healthy 1-y-old infants, which is related to thei r existing Fe stores.