Protective value of dietary copper and iron against some toxic effects of lead in rats.

Both dietary iron and copper were inversely related to lead absorption as indicated by erythrocyte and kidney lead levels, dietary iron having the greatest effect. Kidney copper values were depressed when dietary iron was low, a condition which was worsened by lead. Lead tended to lower heart cytochrome c oxidase especially when dietary copper was low, but also when dietary copper and zinc were high. Lead interfered with hematopoiesis when dietary copper and/or iron were low, the effect being expecially severe when both essential nutrients were low. These results show the importance of copper and iron nutriture and metabolism as factors which reduce lead toxicity, and emphasize the necessity of considering nutritional status in evaluating lead toxicity.