Do multivitamins protect you from disease?

Multivitamins may slightly reduce the risk of cancer but don't prevent heart disease. Keep the focus on diet, not supplements.

Up to half of all adults in the United States may already take a multivitamin. Most probably expect it to make them feel better and prevent common illnesses, even though the evidence has always been a little sketchy. Is the one-a-day multivitamin habit truly healthful—or just wishful thinking?