The role of iron therapy in childhood plumbism

Abstract

Iron deficiency and lead poisoning share common environmental risk factors and both are causes of neurocognitive toxicity. Despite their links epidemiologically, little is known of the effects of iron supplements on lead kinetics and toxicity. Nevertheless, iron is routinely prescribed in children with lead poisoning. Most of the existing data focus on the effects of preexisting iron deficiency on lead absorption. Animal studies demonstrate that iron-deficient animals have increased lead absorption. Lead-poisoned iron-deficient animals treated with iron supplements have demonstrated decreased lead excretion, a factor that might exacerbate lead toxicity while mitigating the effects of iron deficiency. Iron supplements given to children with iron deficiency and lead poisoning have been demonstrated to improve developmental assessment scores, an effect that is independent of blood lead concentration, suggesting that it is solely due to reversal of iron deficiency. Improvements in developmental assessment scores and decreases in blood lead in iron-replete children with lead poisoning secondary to iron supplements have not been demonstrated in clinical studies. Given these factors, the use of iron supplements in lead poisoning should be individualized, and the supplements should be provided only to patients who are iron deficient or who continue to live in lead-exposed housing.