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Take your supplements seriously

Combining medications and dietary supplements

A growing number of adults are taking dietary supplements.

71% of Americans took dietary supplements last year, up three percentage points from 2015.

2016 CRN Consumer Survey on Dietary Supplements

They are also combining multiple prescriptions, over-the-counter medications, and dietary supplements in ways that could lead to serious side effects. In fact, more than 67 percent of older American adults are taking five or more medications or supplements, according to findings published in JAMA Internal Medicine in April 2016.

Dietary supplements contain a variety of ingredients: vitamins, minerals, amino acids, and herbs or other botanicals. Research has confirmed health benefits of some dietary supplements but not others. 

The labeling on many dietary supplements gives the impression they are "natural" and therefore safe. However, "natural" does not necessarily equal "safe." While dietary supplements are regulated by the U.S. Food and Drug Administration (FDA), they are not required to undergo safety testing or FDA approval before they are sold and marketed. Most dietary supplements have not been tested in pregnant women, nursing mothers, or children. 

Some dietary supplements can change the way medication is absorbed and metabolized, and therefore alter its potency. Combining dietary supplements and medications could have dangerous and even life-threatening effects. A few examples: 

  • St. John's Wort, an herbal supplement, can speed the breakdown of many drugs, including drugs for heart disease, depression and birth control pills. This reduces the drugs' effectiveness. Depending on the medication involved, the results can be serious. 
  • Warfarin is a common prescription blood thinner. Taken with a supplement such as omega-3 fish oils, it could increase the risk of bleeding in certain patients. The herbal supplement ginkgo biloba, aspirin, and the supplement vitamin E can each thin the blood. Taking any of these products together may increase the potential for internal bleeding or stroke. 
  • Many supplements have unwanted effects before, during and after surgery. Garlic, vitamin E and fish oil have blood-thinning effects. Some supplements can also interfere with anesthesia, including St. John's wort, ephedra, garlic, and ginseng to name a few. 
  • Antioxidant supplements, like vitamins C and E, might reduce the effectiveness of some types of cancer chemotherapy.

As many as 70% of patients do not discuss their use of supplements with a physician.

National Center for Biotechnology Information (NCBI)

Be smart about supplements

  • Don't take supplements in place of, or in combination with, prescribed medications without your health care provider's approval. 
  • Tell all your health care providers about any supplements, over-the-counter medications and prescriptions you may be taking. Give them a full picture of what you do to manage your health. 

Learn more about dietary supplements on the FDA website External Site. If you or a family member has an adverse reaction to a dietary supplement, report the problem External Site to the FDA. To file a safety report online, visit the Health and Human Services website External Site.

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