Effect of mega doses of vitamin C on bactericidal ativity of leukocytes

Effect of ingesting mega doses of ascorbic acid was studied on the leukocyte function in five normal human subjects. During the first 15 days the subjects received daily supplements of 200 mg of ascorbic acid, and during the next 2 weeks they were given 2 g of vitamin C per day. Supplementation of 200 mg as well as 2 g of ascorbic acid stimulated hexose monophosphate shunt activity of resting leukocytes indicating an increase in resting metabolism. Intakes of 200 mg of ascorbic acid per day did not affect bacterial killing by leukocytes. On the other hand, daily intakes of 2 g of ascorbic acid for 2 weeks significantly impaired bactericidal activity. Four weeks after withdrawal of the viatmin supplementation, bactericidal activity returned to normal.