How Safe Are Your Dietary Supplements?

We’re bombarded daily by commercials that promise everything from weight loss to sexual fulfillment if we just buy the dietary supplement they’re advertising. But how do we know whether the substance is safe, let alone effective? Here, experts from the federal Food and Drug Administration (FDA) outline what you should know about these supposed curatives:

First, the definition: “dietary supplements” include vitamins, minerals, amino acids, herbs or botanicals, the FDA experts say. Some may make specific promises (for example, an herb to get a good night’s sleep), while others are said to have a more general effect: amino acids are the “building blocks” of protein and affect metabolism, while enzyme supplements speed up biochemical reactions.

These supplements come in a variety of forms, including not only capsules and tablets but also energy bars, powders and liquids.

With so many supplements being advertised so frequently, it’s understandable why consumers would think they are safe. But the FDA experts caution you to talk with a health care professional before using any of these products, no matter how benign they seem. “Many supplements contain ingredients that have strong biological effects, and such products may not be safe in all people,” the agency said in a Consumer Update.

(Even some common supplements may have negative effects, the agency says: bleeding before, during or after surgery is a potential side effect of garlic, ginkgo biloba, ginseng, and Vitamin E. Other supplements, such as kava and valerian, act as sedatives and can increase the effects of anesthetics and other medications used during surgery. Before surgery, the FDA says, you should inform your health care professional about all the supplements you use.)

It’s all the more important that consumers check with their physicians because, the FDA emphasizes, federal law doesn’t require dietary supplements to be proven safe to the agency’s satisfaction before they are marketed. But it is illegal to claim that any product is a treatment or cure for a specific disease or that it alleviates the symptoms of a disease.

The FDA experts say that in general, the agency’s role with a dietary supplement product begins only after the product is for sale. Then the FDA has safety-monitoring responsibilities. The agency reviews mandatory reporting of adverse events by a product’s manufacturers and looks at literature (i.e. package inserts) that comes with the supplements. But the agency has limited resources, and reviews claims of products as their resources permit.

When supplements have been recalled, the FDA says, it’s been for a number of reasons including contamination by pesticides and heavy metal; an absence of an ingredient that was said to be in the product; or the presence of more or less of an ingredient than was claimed. In other cases, the products were completely bogus.