THE HEALTH-EFFECTS OF VITAMIN-C SUPPLEMENTATION - A REVIEW

A comprehensive review of the literature indicates that populations wi th long-term consumption of higher than RDA levels of vitamin C (great er than or equal to 60 mg/day) from foods and/or supplements have redu ced risks of cancer at several sites, cardiovascular disease, and cata racts. The safety of higher than RDA intakes of vitamin C is confirmed in eight placebo-controlled, double-blind studies and six non-placebo clinical trials in which up to 10,000 mg of vitamin C was consumed da ily for up to 3 years. There are no clinical data which suggest that v itamin C's enhancement of non-heme iron absorption in individuals with low iron status could be a critical factor in the possible increased risk of heterozygous hemochromatosis-related cardiovascular disease. I n fact, the cumulative data do not confirm that iron status is related to risk of cardiovascular disease. Moreover, higher than RDA intakes of vitamin C have been associated with several indices of lowered card iovascular disease risk including increases in HDL, and decreases in L DL oxidation, blood pressure and cardiovascular mortality.