Effects of iron therapy on infant blood lead levels.

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.