Effect of Minerals and Food on Uptake of Lead from the Gastrointestinal Tract in Humans

Abstract

1 Eight adult male volunteers ingested ²⁰³Pb as chloride with varying amounts of CaCO₃ and NaH₂PO₄. The uptake from the gastrointestinal tract declined progressively as the amount of minerals taken simultaneously was increased, in agreement with the findings of Blake (1980).

2 With four of the volunteers, further tests were done to compare the effect of the two minerals together and separately. With no minerals, uptake averaged 63.3% (range 58.6-66.7%). The two together (200 mg Ca and 140 mg P) reduced it to 10.6% (range 8.6-12.8%), but neither mineral by itself was nearly so effective as the two together.

3 A lamb was injected with ²⁰³Pb and butchered after 6 days. Six volunteers ate the liver or kidneys as part of a meal. Uptake of ²⁰³Pb incorporated in the offal averaged 2.8% (range 1.6-4.7%). When ²⁰³Pb in solution was taken with inactive offal in a similar meal, uptake averaged 3.0% (range 1.7-3.6%). Thus incorporation of ²⁰³Pb in liver or kidney did not affect the uptake.