1. To compare markers of lipid oxidation (urinary isoprostane) and DNA damage (urinary 8-OHdG (urinary 8-hydroxy-2'-deoxyguanosine)) among 3 treatment groups: (iron given between meals (27 mg daily, in a multivitamin-mineral supplement), iron given with meals (27 mg daily, in a multivitamin-mineral supplement) and multivitamin-mineral supplement with no iron, given between meals) at the beginning and end of 3 months of treatment in 114 lactating women.