Bioavailability of iron- and copper-supplemented milk for Mexican school children.

Fortification of dairy products with trace metals requires use of assimilable compounds that do not catalyze off-flavors due to lipid peroxidation but show good biological availability. The Fe(III) and Cu(II) chelates of the promising chelator, lactobionic acid, have been compared to Fe(II) and Cu(II) salts for their ability to improve hematological status in a mildly anemic population. Fe- and Cu-fortified cow milk was administered to children (aged 6 to 15) in the Durango, Mexico, "school lunch" program. Children drank milk providing 20 mg Fe and 3 mg Cu as ferric/cupric lactobionate ("chelate") or ferrous/cupric chloride ("salt") for 5 of 7 days/wk for 3 months. Supplementation with "salt" and "chelate" raised Hb significantly by 1 and 0.3 g/dl, respectively, above the control (unsupplemented) group. No significant change was observed in incremental serum ferritin, serum Fe, or transferrin saturation, or in final serum Cu. Ferric lactobionate shows poorer bioavailability than ferrous ion in the presence of Cu, but milk can be an excellent vehicle for Fe or Cu supplementation.