Iron and manganese uptake by offspring of lactating mice fed a high aluminum diet

High dietary Al can result in lowered tissue Mn and Fe concentrations in weanling mice. Possible mechanisms underlying this effect of Al (altered milk Fe and Mn content, altered absorption or retention of Fe and Mn) were investigated in this experiment. To determine if milk composition was changed, milk was analyzed for Fe and Mn at 0, 3, 7, and 12 days postnatal. To determine if Al influenced absorption and/or retention of Fe and Mn, a single milk meal containing Mn-54 and Fe-59 was administered by gavage to 12 day old pups and tissues were obtained 6 and 24 h later. Pup body and tissue weights were not affected by the high Al diet. Milk from dams fed high Al diets (1000 mu g Al/g, n = 11, Al1000) had similar Fe and Mn concentrations as milk from dams fed a control diet (7 mu g Al/g, n = 11), although Al concentrations were higher. Absorption and tissue distribution of Mn-54 and Fe-59, as determined at the 6 h timepoint, were unaffected by maternal diet group (control n = 16, AL1000 n = 10). However, total retention of both Mn-54 and Fe-59 was 8-10% fewer in the AL1000 pups 24 h after gavage (P = 0.030 for Mn and 0.017 for Fe). These data suggest that high dietary Al during development alters the ability of nursing mouse pups to retain absorbed Fe and Mn.