Two studies found niacin (vitamin B3), a drug used for the prevention of cardiovascular disease, had mixed results for heart health. Published in the New England Journal of Medicine, the studies involved giving at least 1,500 mg of niacin to people with cardiovascular or vascular disease. While niacin improved cholesterol levels and reduced triglyceride levels, it did not seem to reduce risk of heart disease, stroke, or death, and was associated with serious side effects. Critics of these studies point out that the results may have been skewed because the participants were already at high risk for health problems, and asked whether niacin might still be very useful for patients with different health profiles.

Source: New York Times