Dietary Supplements: Benefits, Risks and How They Are Regulated

Dietary supplements are vitamins, minerals, herbs and many other products, meant to add to the diet. They come as pills, capsules, soft gels, powders, gummies, liquids, drinks and bars. Common kinds include:

• vitamins, such as multivitamins, vitamin D and biotin;
• minerals, such as calcium, magnesium and iron;
• herbs and other botanicals, such as echinacea and ginger, and botanical compounds such as caffeine and curcumin;
• amino acids, such as tryptophan and glutamine;
• live microbials, usually called probiotics.

What they can do

Some supplements play an important part in health and help people get enough essential nutrients. Calcium and vitamin D help keep bones strong; fibre helps keep bowels regular; and folic acid, taken by pregnant women, helps prevent certain birth defects. The benefits of some supplements are well established, while others need more study — and supplements should not replace the variety of foods a healthy diet needs.

Risks

Supplements do not go through the testing that drugs do, and many contain ingredients with strong effects on the body. Some interact with medicines, interfere with lab tests, or cause dangerous effects during surgery. Problems are more likely if you:

• combine supplements;
• mix supplements with medicines;
• take too much of some supplements;
• take supplements instead of prescribed medicines.

If you have a bad reaction, stop taking the supplement, get medical care or advice, and report the problem to the Food and Drug Administration (FDA).

Taking them safely

• Tell your health care provider about every supplement you take, and talk to a doctor, nurse, registered dietitian or pharmacist before starting one.
• Don't take more than the label recommends.
• Check with your provider about your supplements before any kind of surgery.
• Read trustworthy information about the supplement.

How supplements are regulated

The Dietary Supplement Health and Education Act of 1994 (DSHEA), which amended the Federal Food, Drug, and Cosmetic Act, defined "dietary supplement" and set the FDA's authority over them.

• No approval before sale. The FDA cannot approve supplements for safety or effectiveness, or approve their labels, before they are sold. Companies are responsible for making sure their products meet the safety standards and the law.
• Labels. Every supplement must carry a Supplement Facts label listing the serving size, servings per container, each dietary ingredient and its amount per serving, and must say on the front that it is a dietary supplement, or use a term such as "herbal supplement" or "calcium supplement."
• Disease claims make it a drug. A product meant to treat, diagnose, cure or prevent a disease is a drug, even if it is labelled as a supplement, and must meet all the rules for drugs.

Because companies can often sell a new supplement without telling the FDA, the agency's role mainly begins once a product is on the market — for example, by periodically inspecting supplement manufacturers.

Sources

• MedlinePlus, U.S. National Library of Medicine, "Dietary Supplements," drawing on the NIH Office of Dietary Supplements. https://medlineplus.gov/dietarysupplements.html
• U.S. Food and Drug Administration, "FDA 101: Dietary Supplements," used for the kinds of supplements, benefits and risks, reporting problems, and regulation: https://www.fda.gov/consumers/consumer-updates/fda-101-dietary-supplements
• Rewritten in hubnx's own words.