Vitamin C

Well known for its effects on diminishing the symptoms of the common cold, vitamin C -- which is a strong antioxidant and can be found in citrus fruits, strawberries, green peppers, tomatoes, and potatoes -- has received some attention for its possible role in reducing the risk of heart disease. Much of the vitamin C research in humans has been based on cohort studies, which follow large groups of people with common characteristics over a long period of time.

In three of five cohort studies, it was found that vitamin C supplementation had no effect on preventing heart disease. However, in a review of nine other cohort studies, those who took over 700 mg of supplemental vitamin C a day were found to have a 24 percent lower risk of heart disease than those who did not take supplements. At this time, the evidence to support taking supplemental vitamin C to prevent heart disease is inconclusive.

There is also evidence suggesting calcium may help lower cholestero