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Take your supplements seriously

Beware of combining medications and dietary supplements

This article was last updated on Sept. 2, 2020.

More people than ever before are taking vitamins and dietary supplements. In fact, according to a survey from the Council for Responsible Nutrition, 77 percent of Americans External Site report consuming dietary supplements. 

Not only are people taking supplements more consistently, they're also combining them with multiple prescriptions and over-the-counter medications. More than 67 percent of older American adults report taking five or more medications or supplements External Site. This combination of dietary supplements and medication could potentially lead to serious side effects.

Be aware of the ingredients in your supplements

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) External Site, 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. 

Keep safety in mind when supplements and medication are taken together

While it's always important to monitor your body's response to supplements, it's even more vital to be aware of possible side effects from combining dietary supplements with prescription medications or medical procedures. Some dietary supplements can change the way medication is absorbed and metabolized, and therefore alter its potency. Some can increase the risk of side effects, like bleeding, or even change your response to anesthesia External Site.

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)

Talk to your doctor to reduce the risk of supplements

Before you start taking vitamins or dietary supplements, it's important to talk to your health care provider. By knowing about any supplements, over-the-counter medications and prescriptions you may be taking, your personal doctor will have a full picture of what you do to manage your health. To get the conversation started, you might want to consider discussing these four things External Site

  1. The reason you're taking the supplements
  2. How you're taking them
  3. The potential risk of taking the supplements
  4. Their effectiveness

In addition to speaking with your doctor about supplements, the FDA also suggests that you take these extra precautions External Site

  • Ask yourself if the dietary supplement claims seem too good to be true, exaggerated or unrealistic.
  • Watch out for extreme claims, like the vitamin will be a "cure-all" or "quick and effective". 
  • Be skeptical about personal testimonials from others who have used the product.  

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.

Healthy Living
Healthy Living