SERUM ASCORBIC-ACID AND CARDIOVASCULAR-DISEASE PREVALENCE IN US ADULTS

To examine the relation between serum ascorbic acid level and the prev alence of cardiovascular disease, we analyzed data from 6,624 U.S, men and women enrolled in the Second National Health and Nutrition Examin ation Sun-ep. We calculated odds ratios and 95% confidence intervals t o estimate the relative prevalence. of cardiovascular disease, defined as self-reported coronary heart disease or stroke, or a diagnosis of peripheral vascular disease based on physical examination. Serum ascor bic acid levels were independently associated with prevalence of coron ary heart disease and stroke; a 0.5-mg per dl increase in serum ascorb ic acid level was associated with an 11% reduction in coronary heart d isease and stroke prevalence. We also analyzed the relation of ascorbi c acid, grouped into low to marginal, normal, and saturation serum cat egories, to cardiovascular disease. Compared with participants with lo w to marginally low serum ascorbic acid levels, we found a 27% decreas ed prevalence of coronary heart disease (95% confidence interval = 10- 41%) and a 26% decreased prevalence of stroke (95% confidence interval = 3-44%) among participants in the highest serum ascorbic acid catego ry. Serum ascorbic acid levels were not consistently associated with p revalence of peripheral vascular disease. These results are consistent with the hypothesis that increased ascorbic acid intake may decrease the risk of coronary heart disease and stroke.