Objectives: To determine the effects of iron therapy on blood lead levels in infants with mildly elevated lead levels and varied iron status.
Methods: Infants from a community-derived sample in Costa Rica were categorized into five groups. Group 1 had iron-deficiency anemia with hemoglobin levels <or=105 g/L. Infants in group 2 were iron-deficient with intermediate hemoglobin levels (between 106-119 g/L). These groups were treated with intramuscular iron or 3 months of oral iron. Group 3 (nonanemic iron-deficient) and group 4 (nonanemic iron-depleted) were treated with 3 months of oral iron. Group 5 (iron-sufficient) received oral placebo.
Results: After 3 months of oral iron therapy, nonanemic iron-depleted infants had the greatest decrease in lead levels, followed by nonanemic iron-deficient infants and iron-deficient infants with hemoglobin levels <120 g/L. Lead levels increased among iron-deficient infants with hemoglobin levels <120 g/L who received intramuscular iron and iron-sufficient nonanemic infants who received placebo.
Conclusions: Changes in lead levels corresponded closely to changes in iron status and were plausible in terms of absorption mechanisms for lead and iron. Correcting and/or preventing iron deficiency appear to be rapid and effective means of improving infant lead levels, even in nonanemic infants.