We are measuring maternal plasma and breast milk lead levels as these are the most direct sources of fetal and infant lead exposures, and recent research suggests that maternal venous blood lead levels do not adequately reflect either of these parameters. We are testing the hypothesis that supplements will significantly decrease urinary NTX, plasma lead, and breast milk lead levels. We are also exploring the relationship of plasma lead levels to birth anthropometry measures. This research, if successful, may provide a means of preventing secondary toxicity from accumulated lead burdens among women of reproductive age.