A study following more than 85,000 nurses during a 16-year period found that those who used vitamin C supplements, significantly reduced the risk of heart disease. After adjusting for age, smoking and a variety of other coronary risk factors, vitamin C supplement use (with total intakes of more than 359 mg/day from diet plus supplements) was associated with a 38 percent reduction in heart disease. Vitamin C may have a protective role in preventing heart disease by its anti-oxidant nature that helps inhibit the development of plaque.
Stavroula and others. "Vitamin C and Risk of Coronary Heart Disease in Women." Journal of the American College of Cardiology. 2003;42(3):246-52.