If you want to get the nutrients you know you don't get in your diet, you do what tens of millions of other Americans do: You take a multivitamin.
"Many adults don't eat a varied enough diet to get the proper amounts of all vitamins and minerals, so a vitamin is a good way to prevent deficiency," said Dr. J. Michael Gaziano, Brigham and Women's Hospital.
But many take vitamins because of the perceived benefits beyond that. Previous studies suggested multivitamins can help prevent heart attack and stroke.
Brigham and Women's Hospital researchers conducted a randomized controlled trial on more than 14,000 male physicians. Some took vitamins. Others took a placebo.
In the 14-year study published in the Journal of the American Medical Association, researchers found vitamin supplements didn't have any effect on major cardiovascular outcomes.
"When we looked further at some other cardiovascular endpoints such as fatal stroke, ischemic stroke, hemorrhagic stroke, we saw a consistent lack of effect for taking a multivitamin on those outcomes," said Dr. Howard Sesso, Brigham and Women's Hospital.
But they did find a daily multivitamin did offer a modest reduction in total cancer among men who took supplements.
"Given the findings that we saw for total cancer there might be still some compelling reasons to consider taking a daily multivitamin in the prevention of cancer," said Sesso.
How this study applies to women is unknown, but last year an Archives of Internal Medicine report of more than 38,000 women showed supplement use was linked with a 2-percent higher risk of death.
The National Institutes of Health paid for most of the male physician study.
Pfizer Inc., which makes the Centrum Silver multivitamin used in the study, supplied the pills.