November 2022

Dietary supplements — vitamins, minerals, herbs, or other botanicals — are wildly popular. According to the Centers for Disease Control and Prevention (CDC), more than 57% of U.S. adults use dietary supplements. This includes everything from multivitamins and probiotics to fish oil and ginseng.

The Food and Drug Administration (FDA) doesn’t regulate dietary supplements as strictly as prescription medications. Instead, companies that manufacture supplements must have evidence that their products are safe.

So, it’s best to do your homework when taking any kind of dietary supplement. Here are some things to keep in mind:

• “Natural” doesn’t always equal “safe.” Herbal ingredients can have strong effects. The all-natural botanicals comfrey and kava, for instance, can harm your liver. Dietary supplements may interact with your medications. For example, St. John’s wort can make some drugs less effective — including birth control pills, treatments for organ transplants, and medicines that treat HIV/AIDS, heart disease, and depression. Vitamin C might reduce the effectiveness of some types of chemotherapy for cancer.
• Turmeric, ginkgo biloba, and vitamin E all have anticoagulant effects, so you shouldn’t mix them with blood thinners. Milk thistle, which some people take for liver and heart health, may lower blood sugar and cause problems for people on diabetes medicine.
• Many dietary supplements haven’t been tested in pregnant women, nursing mothers, or children. (Taking a prenatal vitamin or multivitamin, however, is unlikely to cause harm.)
• If you’re having surgery, you may need to stop taking some supplements, including ginseng and gingko. Some supplements may increase the chance of bleeding or change your body’s response to anesthesia.

When in doubt about an herbal or nutritional supplement, ask your pharmacist or doctor. Bring a list of all the supplements and medications you take whenever you visit any healthcare provider, including dentists and pharmacists.