Interactions of lead, calcium, vitamin D, and nutrition in lead-burdened children

Abstract

This study was undertaken to evaluate relationships between blood or serum levels of lead (Pb), calcium, and 25-hydroxyvitamin D (25-OHD), within the framework of a nutritional survey of lead-burdened children. The results demonstrate that: regardless of blood Pb concentration and season of the year, serum 25-OHD concentration reflects vitamin D intake; high blood Pb (greater than or equal to 60 microgram/dl) was associated with decreased levels of 25-OHD (18+/--1 ng/ml vs. 32+/- in controls, P less than .001); concentrations Pb and calcium were inversely correlated in control and lead-burdened children; and children in the high blood Pb group (greater than or equal to 60 microgram/dl) had lower mean daily intakes of both calcium (610 +/- 20 mg vs. 770 +/- 20 in controls, P less than .001) and vitamin D (210 +/- 17 IU vs. 325 +/- 20 in controls, P less than .001). These data indicate that, in Pb-burdened children, multiple factors modify the absorption and toxicity of Pb, and relative vitamin D deficiency, not excess, is associated with high blood Pb levels. Assessment of nutrition, calcium metabolism, and vitamin D status is recommended in evaluating children known to have undue absorption of Pb.