11 Facts You Need to Know About Dietary Supplements

While some studies have associated multivitamin use with minor health benefits, Joe Leech, R.D., founder of DietsvsDisease.org points to a 2013 review of more than 25 vitamin supplement trials conducted by the U.S. Preventive Services Task Force, which concluded that vitamin supplements had no notable effect on the reduction of cancer risk.
“When you consider that 80 percent of vitamin supplement users are taking them to optimize health and prevent disease, you realize what a big waste of money they are,” he said. “My take is that unless you are supplementing a deficiency or particular health condition—less than 1 in 5 of users—then multivitamins are useless.”
For the majority of Americans, dietary supplements probably aren’t offering all of the health benefits they think they’re getting. Yet, for some, supplementation may be necessary. If you currently use a supplement or are thinking about starting one, these important facts can help you determine whether or not it’s worth your while.

Multivitamins may help prevent cancer...

Physicians’ Health Study II (PHS II), the largest clinical trial of vitamin supplements to date, found that after 10 years, multivitamin users had a slightly reduced risk for developing cancer. “Until now, the only things proven to prevent cancer were stopping smoking and never starting,” said Dr. J. Michael Gaziano, a cardiologist at Harvard-affiliated Brigham and Women’s Hospital and VA Boston Healthcare, and one of the leaders of the PHS II study. “Now we know that multivitamins provide a modest benefit.” Still, the Harvard Medical School (HMS) says these results should not be overplayed.