[Effect of 2-week ascorbic acid supplementation on plasma lead levels in workers occupationally exposed to lead]

The role of ascorbic acid [AA] in plasma lead reduction under lead exposure conditions, has been investigated in both human and animal studies for several decades. These studies had contradictory results, especially concerning lead toxicokinetics. This investigation has been performed to study the effects of ascorbic acid supplementation on plasma lead levels of workers who were occupationally exposed to lead. In a randomized, double-blind, placebo- controlled clinical trial, a total of 24 men were randomly divided into two similar groups. Each group received one of the following daily supplements for two weeks 1000mg AA in cases and placebo [starch] in controls. At baseline, at the end of the 2 week supplementation, and also 4 weeks after the end of the supplementation, plasma and total blood ascorbic-acid levels as well as plasma lead levels were measured. The differences between the ascorbic acid, blood lead as well as plasma lead levels in 2 groups and also in different stages were assessed. Results indicated that at the end of a 2 week supplementation, lead plasma levels in cases significantly decreased compared to those of the controls [p<0.05] and also to baseline levels [p<0.01]. In addition, 4 weeks after the end of the supplementation, plasma levels of lead decreased significantly in case group compared to those of the controls [p<0.05] and also to baseline levels [p<0.05]. Using AA supplementation can be considered as a useful harmless, economical and convenient prophylactic agent for lead-exposed population