High plasma vitamin C associated with high plasma HDL- and HDL2 cholesterol.

High plasma vitamin C may lower risk of cardiovascular disease as indicated by direct association with plasma high-density-lipoprotein (HDL) cholesterol and HDL2 cholesterol. Plasma lipids and vitamin C were determined in 316 women and 511 men (aged 19-95 y). After adjustment for age, sex, obesity, and smoking, plasma vitamin C was directly associated with HDL- (P = 0.01) and HDL2 cholesterol (P = 0.0002). When men and women with diseases that might affect lipids were excluded, associations between plasma vitamin C and HDL- and HDL2 cholesterol persisted, though the relationships were strongest in older men. Comparisons of diets in a subset (n = 485) who completed 7-d diet records were made. Total fat, saturated fatty acids, energy from fat, and cholesterol intakes were not associated with plasma vitamin C. Mean intakes of vitamin C were well above recommended dietary allowances. These findings suggest that high plasma concentrations of vitamin C may lower atherogenic risk.