Effect of minerals and food on uptake of lead from the gastrointestinal tract in humans.

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 mgCa and 140 mgP) 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.