Vitamin C and cardiovascular risk factors. The concept that ascorbic acid (vitamin C) supplementation protects against coronary heart disease developed in the late 1970s when vitamin C intakes in industrialized nations were lower than at present. Supplementation was then shown to lower plasma total cholesterol and, among some elderly men, to raise high-density lipoprotein cholesterol. However, among people in initially good vitamin C nutriture, these effects are usually not seen. In five populations of essentially healthy people, blood pressure has been found to correlate negatively with vitamin C status. Recently, in a placebo-controlled, double-blinded study, extra ascorbic acid for 6 wk was observed to lower systolic and pulse pressure in a small group of borderline hypertensive subjects. 