Be Smart About Using Dietary Supplements

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People take dietary supplements for various reasons. Some want to increase their energy or help with weight loss. Others simply want to enhance their overall health.

Dietary supplements are just what the name suggests. They contain ingredients to supplement—or add to—your diet. The ingredient could be a vitamin, mineral, amino acid, herb, or enzyme. Dietary supplements usually come in pill, liquid or powder form. You can buy some as a tea or extract to drink. Others come as a nutrition bar or a chew. 

It’s important to realize any dietary supplement has the potential to cause problems. And some can have harmful side effects. That's especially true if you combine them with certain prescription medications or if you have an existing medical problem. Learn the answers to the following questions before taking any dietary supplement. 

What are the benefits?

Dietary supplements can be beneficial. Some may help reduce the risk for certain diseases. Others may help you be healthier overall. 

For instance, your body needs vitamin D. It's important for healthy bones. But, it can be hard to get enough of this vitamin naturally. Taking a supplement provides an extra source of vitamin D. Another example is folic acid. Taking it before and during early pregnancy helps prevent certain birth defects.  

Check with your doctor before starting a supplement to find out about the specific benefits for you.

What are the risks?

You might see words like "safe" or "natural" on the labels, but dietary supplements do come with risks. One new study estimates about 23,000 people in the United States go to an emergency room each year for bad reactions to supplements. About 10% of them are admitted to the hospital. 

Many people in the study who had problems with supplements were young adults—20 to 34 years old—or senior citizens. Others were children who had taken supplements when they weren't supervised. The reactions varied by age group. Among young adults, problems included heart palpitations, chest pain, and an abnormally fast heartbeat from taking weight loss or energy supplements. People 65 or older often choked or had trouble swallowing supplements in pill form.

There are other risks, too. Most dietary supplements have not been tested for use in pregnant women, nursing women, or small children. Other situations in which taking a dietary supplement without medical supervision could be dangerous include: 

  • If you have diabetes or an irregular heartbeat. Some ingredients in supplements can interact with prescription medications for these conditions.

  • If you’re planning to have surgery. Some supplements can increase your risk of bleeding or of having a bad reaction to anesthesia.

  • If you're having cancer treatment. This is a time when you need to be especially careful about taking supplements. Some can cause reactions, including severe skin issues, if you're having radiation treatments. Some supplements also interact badly with chemotherapy drugs.

How can I take supplements safely?

All of this makes it very important to talk with your doctor before taking dietary supplements. These products aren’t regulated like over-the-counter and prescription medications are. They don’t go through the same testing and approval process. Getting information from your doctor can help you make choices that are right for you. 

Be sure to ask these questions about any dietary supplement: 

  • What are the potential benefits and risks for me?
  • What is the best dosage for me?
  • When can I expect to see results?

Finally, before you buy a dietary supplement, read and compare labels. Check out the "Supplement Facts" panel to see what's in the product, including any fillers or flavors. Look for the seal of a reputable testing organization. This could be U.S. Pharmacopeia (USP), (CL), or NSF International. A seal doesn't guarantee that a supplement is safe or effective. But, it does independently verify the ingredient identity, strength, quality and purity.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2019 Dec 19
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.

  1. Dietary Supplements: What You Need to Know. Office of Dietary Supplements/NIH.   

  2. Folic Acid and Birth Defects. Centers for Disease Control and Prevention.

  3. Geller AI, Shehab N, Weidle NJ, Lovegrove MC, Wolpert BJ, et al. Emergency department visits for adverse events related to dietary supplements. N Engl J Med. 2015 Oct 15;373(16):1531-40.

  4. Questions and Answers on Dietary Supplements. U.S. Food and Drug Administration. 

  5. Risks and Side Effects of Dietary Supplements. American Cancer Society.

  6. Tips for Dietary Supplement Users. U.S. Food and Drug Administration.