Although vitamin C, ascorbic acid, is one of the most important antioxidants in extracellular fluids, it traps peroxyl radicals and inhibits lipid peroxidation. Several studies indicate that there is no apparent benefit in the prevention of cardiovascular disease with use of vitamin C.
1. The Nurse’s Prospective Observational Study of 87,000 female nurses followed for a mean of 8 years and health professionals study in which 39,000 male health professionals were followed for 4 years showed no reduced risk for coronary revascularization, myocardial infarction, or death from coronary heart disease among persons using vitamin C.
2. A randomized controlled trial carried out in China found no reduction in total mortality or mortality from cardiovascular diseases in 29,584 healthy adults given vitamin C over 5 years.
Vitamin C is known to have antioxidant properties, but its effects appear to be modest and may only be observed in patients at very high risk; this includes patients with heart failure in whom vitamin C has not been adequately tested, particularly in combination with vitamin E. Ascorbic acid has been shown to normalize endothelial function by restoring NO-mediated vasodilatation of endothelium in patients with hypertension, but it does not cause a lowering of blood pressure.