Dietary Supplements: Making Sure Hype Doesn't Overwhelm Science

by Food and Drug Administration (FDA)

When it comes to dietary supplements, consumers have the right to expect safety and to have information about products they choose so they know what they're getting, according to the Food and Drug Administration.

Without the proper safety data, however, says Michael Taylor, FDA deputy commissioner for policy, the agency has no way to ensure that many consumers taking supplements won't be at risk.

FDA is responsible under the Federal Food, Drug, and Cosmetic (FD&C) Act for ensuring that manufacturers of foods, including dietary supplements, provide safe ingredients for their products as well as accurate, complete labeling that is truthful and not misleading.

Defining a Dietary Supplement

The Nutrition Labeling and Education Act of 1990 (NLEA), which amended the FD&C Act, refers to dietary supplements of vitamins, minerals, herbs, or other similar nutritional substances.

As commonly consumed, dietary supplements in the marketplace in the form of capsules, tablets, liquids, or powders' include vitamins; essential minerals; protein; amino acids; botanicals such as ginseng and yohimbe; extracts from animal glands; garlic extract; fish oils; fibers such as acacia and guar gum; compounds not generally recognized as foods or nutrients, such as bioflavonoids, enzymes, germanium, nucleic acids, para-aminobenzoic acid, and rutin; and mixtures of these ingredients.

The Council for Responsible Nutrition, a trade organization for supplement manufacturers, reports that in 1991 some 40 percent of American adults took vitamin supplements, and retail sales for over-the- counter nutritional products totaled several billion dollars.

Most vitamin and mineral supplements usually pose no safety concerns for the general population. Scientists generally know more about these nutrients than about ingredients used in other types of dietary supplements. And, most vitamin and mineral products are accurately labeled for content and are offered at moderate potencies.

"Our main concerns," Taylor says, "are with the array of other products that have unsubstantiated safety" such as amino acids and herbs and other botanicals. We know very little about some of these products ingredients.

Diet and Disease

Recent attention to a possible effect of diet in reducing the risk of certain diseases has raised new safety issues about how FDA should regulate dietary supplements. Growing scientific support for such benefits and increased consumer interest in improving health through diet provided much of the impetus for provisions of the NLEA to allow health claims for foods. (See "Starting This Month: Look for Legit' Health Claims on Foods" in the May 1993 FDA Consumer.)

But, because manufacturers believed FDA would limit claims on their supplements under the NLEA, they conducted a rigorous consumer campaign to get Congress to limit FDA's authority.

"They wanted us to adopt a more relaxed standard for claims on supplements than Congress had adopted for conventional foods," Taylor says.

When the Dietary Supplement Act of 1992 became law on Oct. 29, 1992, a year's moratorium was imposed on implementation of the NLEA with respect to supplements. But it called for FDA to propose NLEA- based labeling rules for supplements by June 15, 1993, which the agency did (see "FDA's Proposals"), and to issue final rules in December.

In October, FDA published a proposed rule on allowing a health claim on foods, including supplements that are good sources of folic acid. The claim would discuss the link between folic acid intake by women of childbearing age and a reduced risk of neural tube birth defects in newborns. The agency also proposed amending its food additive rule for folic acid and its standard of identity to require the addition of folic acid to enriched' grain products.

FDA is working with manufacturers and scientists on other potential health claims' such as a claim associating antioxidant vitamins like vitamin C with a reduced risk of cancer and other diseases.

Potentially Unsafe Supplements

While FDA is open to exploring new evidence on the relationships between diet and disease, Taylor says, the agency is concerned that increased attention to these relationships will increase the potential for wider use of possibly unsafe supplements (such as amino acids for bodybuilding) and for development of more untested products. Safety and misleading labeling are prime concerns. FDA is not proposing to regulate dietary supplements as drugs. But if a supplement makes drug claims or contains a substance already regulated as a drug, then consumers deserve to have information about the product's safety and effectiveness, as they do for drugs.

"FDA certainly does not regulate personal choice or the practice of medicine," Taylor says. "But we know that many supplements are sold in drug-like formulations and potencies, yet they haven't been subjected to the safety controls of FDA's drug approval process."

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.