The National Academies of Science, Engineering and Medicine recommends that most adults get about 600 international units of vitamin D per day through food or supplements, increasing that dose to 800 IUs per day for those 70 or older. essgee51/Flickr hide caption
Creatine's popularity among adult athletes as a way to build muscle has prompted many young people to want to try it, too. Tara Moore/Getty Images hide caption
Eating healthy will do more for your immune system than megadoses of supplements. Gillian Blease/Ikon Images/Getty Images hide caption
Yana Shapiro relaxes while taking an intravenous vitamin treatment at RestoreIV in Philadelphia. Emma Lee/WHYY hide caption
Asafa Powell of Jamaica was barred from competition after testing positive for the stimulant oxilofrine. Streeter Lecka/Getty Images hide caption
In northern climes, the winter sun is too weak for people to generate vitamin D on their own, and it can be hard to get enough in food. iStockphoto hide caption
In addition to heart problems triggered by some supplements, emergencies often arise when kids swallow dietary supplements meant for adults, according to the CDC analysis, or when older adults choke on the pills. Lee Woodgate/Ikon Images/Corbis hide caption
Turning to over-the-counter supplements to get ripped can contribute to physical and psychological issues. iStockphoto hide caption
DNA tests were run on supplements claiming to contain ginko bilboa, St. John's wort, ginseng and echinacea. Chris Hondros/Getty Images hide caption
Ideally, we'd all eat super healthful diets. But that's not the world we live in, and multivitamins may help bridge the nutritional gaps. Jasper White/Getty Images hide caption
People can make vitamin D when exposed to sunshine. But many people in North America never get enough sun to do that. iStockphoto hide caption
Wouldn't it be great if this stuff really did cause quick painless weight loss? iStockphoto hide caption
Even versions of Zi Xiu Tang Bee Pollen labeled "genuine" and "anti-counterfeit" have been found to contain the drug sibutramine, which was supposed to come off the U.S. market in 2010 for safety reasons. Food and Drug Administration hide caption
Dietary supplements are generally defined as vitamins, minerals, herbs and extracts. They're regulated as a unique category of food by the Food and Drug Administration. iStockphoto.com hide caption
With osteoarthritis, knees become swollen and stiff, and cartilage can degenerate. Ted Kinsman/Science Source hide caption
If only it was as simple as popping a supplement and being set for life. But alas, no. iStockphoto.com hide caption
Ads often tout dietary supplements and vitamins as "natural" remedies. But studies show megadoses of some vitamins can actually boost the risk of heart disease and cancer, warns Dr. Paul Offit. iStockphoto.com hide caption
Raw, green coffee beans. To roast or not? Aidan/via Flickr hide caption
Forgoing calcium supplements is a fine approach for most people, a preventive services panel says. iStockphoto.com hide caption
Some sports supplements contain the ingredient DMAA. The FDA has warned that DMAA may not be safe. iStockphoto.com hide caption
Despite public health campaigns urging women in the U.S. to take folic acid, many are still not taking the supplements when they become pregnant. iStockphoto.com hide caption
There might be much more caffeine than you think in those supplements you're taking. There also might be much less. Janine Lamontagne/iStockphoto hide caption
