Nearly 58% of adults and 35% of children in the U.S. take dietary supplements, spending more than $50 billion each year. Many myths about supplements fuel their popularity. While they are beneficial in some cases, most people do not need them. Our research team has led several of the nation’s largest randomized clinical trials of supplements, including vitamin D, omega-3 fatty acids, and multivitamins to determine when supplements can be useful.
1
Not All Supplements are Natural and Safe.
Unlike prescription medications, the U.S. Food and Drug Administration does not regulate dietary supplements for safety or effectiveness, and most haven’t been rigorously tested for either. Some supplements are synthetic and are neither natural nor safe. To ensure quality-control testing of a supplement, check the label for seals of approval from U.S. Pharmacopeia, National Science Foundation, or ConsumerLab.com, which indicate they have the nutrient dose noted on the label and are free of microbes and heavy metals.
2
SUPPLEMENTS ARE NO SUBSTITUTE FOR A HEALTHY DIET AND LIFESTYLE.
Many chronic diseases are largely preventable, and the best strategies are to follow a healthy and balanced diet, be physically active, don’t smoke, control blood pressure and cholesterol, and stay socially and cognitively engaged.
3
MOST PEOPLE WITH HEALTHY, BALANCED DIETS DO NOT NEED SUPPLEMENTS.
Studies show certain supplements are helpful during particular life stages, such as pregnancy and at older ages, or for those with specific health conditions, such as malabsorption, celiac disease, Crohn’s disease, pernicious anemia, or macular degeneration.
4
Some supplements CAUSE NEGATIVE INTERACTIONS.
Tell your doctors about all supplements you take. Prior to any lab test, procedure, surgery, or new prescription (especially blood thinners), ask whether you should stop taking them.
5
Mega-dosing of supplements can cause harm.
Too much vitamin A can damage your liver, weaken bones, affect vision, or lead to birth defects in newborns. Excess vitamin B6 can cause nervous system damage. Excess vitamin D can cause high calcium in the blood and urine, as well as kidney problems, and excess vitamin E can cause bleeding.
By JoAnn Manson, MD, MPH, DrPH, chief of the Division of Preventive Medicine; Michael and Lee Bell Professor of Women’s Health