Set between a Chinese restaurant and a pizza and sub sandwich eatery, a Rockville health food store offers yet another brand of edible items: Bottled herbs like cat's claw, dandelion root, and blessed thistle. Vitamins and minerals in varying doses. Herbal and nutrient concoctions whose labels carry claims about relieving pain, "energizing" and "detoxifying" the body, or providing "guaranteed results." 

This store sells dietary supplements, some of the hottest selling items on the market today. Surveys show that more than half of the U.S. adult population uses these products. In 1996 alone, consumers spent more than $6.5 billion on dietary supplements, according to Packaged Facts Inc., a market research firm in New York City.

But even with all the business they generate, consumers still ask questions about dietary supplements: Can their claims be trusted? Are they safe? Does the Food and Drug Administration approve them?

Many of these questions come in the wake of the 1994 Dietary Supplement Health and Education Act, or DSHEA, which set up a new framework for FDA regulation of dietary supplements. It also created an office in the National Institutes of Health to coordinate research on dietary supplements, and it called on President Clinton to set up an independent dietary supplement commission to report on the use of claims in dietary supplement labeling.

In passing DSHEA, Congress recognized first, that many people believe dietary supplements offer health benefits and second, that consumers want a greater opportunity to determine whether supplements may help them. The law essentially gives dietary supplement manufacturers freedom to market more products as dietary supplements and provide information about their products' benefits--for example, in product labeling.

The Council for Responsible Nutrition, an organization of manufacturers of dietary supplements and their suppliers, welcomes the change. "Our philosophy has been ... to maintain consumer access to products and access to information [so that consumers can] make informed choices," says John Cordaro, the group's president and chief executive officer.

But in choosing whether to use dietary supplements, FDA answers consumers' questions by noting that under DSHEA, FDA's requirement for premarket review of dietary supplements is less than that over other products it regulates, such as drugs and many additives used in conventional foods.

This means that consumers and manufacturers have responsibility for checking the safety of dietary supplements and determining the truthfulness of label claims.

Information that will be required on the labels of dietary supplements includes:

Traditionally, dietary supplements referred to products made of one or more of the essential nutrients, such as vitamins, minerals, and protein. But DSHEA broadens the definition to include, with some exceptions, any product intended for ingestion as a supplement to the diet. This includes vitamins; minerals; herbs, botanicals, and other plant-derived substances; and amino acids (the individual building blocks of protein) and concentrates, metabolites, constituents and extracts of these substances.

It's easy to spot a supplement because DSHEA requires manufacturers to include the words "dietary supplement" on product labels. Also, starting in March 1999, a "Supplement Facts" panel will be required on the labels of most dietary supplements.

Dietary supplements come in many forms, including tablets, capsules, powders, softgels, gelcaps, and liquids. Though commonly associated with health food stores, dietary supplements also are sold in grocery, drug and national discount chain stores, as well as through mail-order catalogs, TV programs, the Internet, and direct sales.

FDA oversees safety, manufacturing and product information, such as claims, in a product's labeling, package inserts, and accompanying literature. The Federal Trade Commission regulates the advertising of dietary supplements.

One thing dietary supplements are not is drugs. A drug, which sometimes can be derived from plants used as traditional medicines, is an article that, among other things, is intended to diagnose, cure, mitigate, treat, or prevent diseases. Before marketing, drugs must undergo clinical studies to determine their effectiveness, safety, possible interactions with other substances, and appropriate dosages, and FDA must review these data and authorize the drugs' use before they are marketed. FDA does not authorize or test dietary supplements.

A product sold as a dietary supplement and touted in its labeling as a new treatment or cure for a specific disease or condition would be considered an unauthorized--and thus illegal--drug. Labeling changes consistent with the provisions in DSHEA would be required to maintain the product's status as a dietary supplement.

Another thing dietary supplements are not are replacements for conventional diets, nutritionists say. Supplements do not provide all the known--and perhaps unknown--nutritional benefits of conventional food.

As with food, federal law requires manufacturers of dietary supplements to ensure that the products they put on the market are safe. But supplement manufacturers do not have to provide information to FDA to get a product on the market, unlike the food additive process often required of new food ingredients. FDA review and approval of supplement ingredients and products is not required before marketing.

Food additives not generally recognized as safe must undergo FDA's premarket approval process for new food ingredients. This requires manufacturers to conduct safety studies and submit the results to FDA for review before the ingredient can be used in marketed products. Based on its review, FDA either authorizes or rejects the food additive.

In contrast, dietary supplement manufacturers that wish to market a new ingredient (that is, an ingredient not marketed in the United States before 1994) have two options. The first involves submitting to FDA, at least 75 days before the product is expected to go on the market, information that supports their conclusion that a new ingredient can reasonably be expected to be safe. Safe means that the new ingredient does not present a significant or unreasonable risk of illness or injury under conditions of use recommended in the product's labeling.

The information the manufacturer submits becomes publicly available 90 days after FDA receives it.

Another option for manufacturers is to petition FDA, asking the agency to establish the conditions under which the new dietary ingredient would reasonably be expected to be safe. To date, FDA's Center for Food Safety and Applied Nutrition has received no such petitions.

Under DSHEA, once a dietary supplement is marketed, FDA has the responsibility for showing that a dietary supplement is unsafe before it can take action to restrict the product's use. This was the case when, in June 1997, FDA proposed, among other things, to limit the amount of ephedrine alkaloids in dietary supplements (marketed as ephedra, Ma huang, Chinese ephedra, and epitonin, for example) and provide warnings to consumers about hazards associated with use of dietary supplements containing the ingredients. The hazards ranged from nervousness, dizziness, and changes in blood pressure and heart rate to chest pain, heart attack, hepatitis, stroke, seizures, psychosis, and death. The proposal stemmed from FDA's review of adverse event reports it had received, scientific literature, and public comments. FDA has received many comments on the 1997 proposal and was reviewing them at press time.

Also in 1997, FDA identified contamination of the herbal ingredient plantain with the harmful herb Digitalis lanata after receiving a report of a complete heart block in a young woman. FDA traced all use of the contaminated ingredient and asked manufacturers and retailers to withdraw these products from the market. (For information about other potentially dangerous dietary supplements, see "Supplements Associated with Illnesses and Injuries.")

DSHEA also gives FDA authority to establish good manufacturing practices, or GMPs, for dietary supplements. In a February 1997 advance notice of proposed rulemaking, the agency said it would establish dietary supplement GMPs if, after public comment, it determined that GMPs for conventional food are not adequate to cover dietary supplements, as well. GMPs, the agency said, would ensure that dietary supplements are made under conditions that would result in safe and properly labeled products. At press time, FDA was reviewing comments on the 1997 notice.

Some supplement makers may already voluntarily follow GMPs devised, for example, by trade groups.

Besides FDA, individual states can take steps to restrict or stop the sale of potentially harmful dietary supplements within their jurisdictions. For example, Florida has banned some ephedra-containing products, and other states have said they are considering similar action.

Also, the industry strives to regulate itself, the Council for Responsible Nutrition's Cordaro says. He cites the GMPs that his trade group and others developed for their member companies. FDA is reviewing these GMPs as it considers whether to pursue mandatory industry-wide GMPs. Another example of self-regulation, Cordaro says, is the voluntary use of a warning about ephedra products that his organization drafted. He says that about 90 percent of U.S. manufacturers of products containing ephedra alkaloids now use this warning label.

Claims that tout a supplement's healthful benefits have always been a controversial feature of dietary supplements. Manufacturers often rely on them to sell their products. But consumers often wonder whether they can trust them.

Under DSHEA and previous food labeling laws, supplement manufacturers are allowed to use, when appropriate, three types of claims: nutrient-content claims, disease claims, and nutrition support claims, which include "structure-function claims."

Nutrient-content claims describe the level of a nutrient in a food or dietary supplement. For example, a supplement containing at least 200 milligrams of calcium per serving could carry the claim "high in calcium." A supplement with at least 12 mg per serving of vitamin C could state on its label, "Excellent source of vitamin C."

Disease claims show a link between a food or substance and a disease or health-related condition. FDA authorizes these claims based on a review of the scientific evidence. Or, after the agency is notified, the claims may be based on an authoritative statement from certain scientific bodies, such as the National Academy of Sciences, that shows or describes a well-established diet-to-health link. As of this writing, certain dietary supplements may be eligible to carry disease claims, such as claims that show a link between:

Nutrition support claims can describe a link between a nutrient and the deficiency disease that can result if the nutrient is lacking in the diet. For example, the label of a vitamin C supplement could state that vitamin C prevents scurvy. When these types of claims are used, the label must mention the prevalence of the nutrient-deficiency disease in the United States.

These claims also can refer to the supplement's effect on the body's structure or function, including its overall effect on a person's well-being. These are known as structure-function claims.

Examples of structure-function claims are:

Manufacturers can use structure-function claims without FDA authorization. They base their claims on their review and interpretation of the scientific literature. Like all label claims, structure-function claims must be true and not misleading.

Structure-function claims can be easy to spot because, on the label, they must be accompanied with the disclaimer "This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease."

Manufacturers who plan to use a structure-function claim on a particular product must inform FDA of the use of the claim no later than 30 days after the product is first marketed. While the manufacturer must be able to substantiate its claim, it does not have to share the substantiation with FDA or make it publicly available.

If the submitted claims promote the products as drugs instead of supplements, FDA can advise the manufacturer to change or delete the claim.

Because there often is a fine line between disease claims and structure-function claims, FDA in April 1998 proposed regulations that would establish criteria under which a label claim would or would not qualify as a disease claim. Among label factors FDA proposed for consideration are:

FDA's proposal is consistent with the guidance on the distinction between structure-function and disease claims provided in the 1997 report by the President's Commission on Dietary Supplement Labels.

If shoppers find dietary supplements whose labels state or imply that the product can help diagnose, treat, cure, or prevent a disease (for example, "cures cancer" or "treats arthritis"), they should realize that the product is being marketed illegally as a drug and as such has not been evaluated for safety or effectiveness.

FTC regulates claims made in the advertising of dietary supplements, and in recent years, that agency has taken a number of enforcement actions against companies whose advertisements contained false and misleading information. The actions targeted, for example, erroneous claims that chromium picolinate was a treatment for weight loss and high blood cholesterol. An action in 1997 targeted ads for an ephedrine alkaloid supplement because they understated the degree of the product's risk and featured a man falsely described as a doctor.

Consumers need to be on the lookout for fraudulent products. These are products that don't do what they say they can or don't contain what they say they contain. At the very least, they waste consumers' money, and they may cause physical harm.

Fraudulent products often can be identified by the types of claims made in their labeling, advertising and promotional literature. Some possible indicators of fraud, says Stephen Barrett, M.D., a board member of the National Council Against Health Fraud, are:

Though often more difficult to do, consumers also can protect themselves from economic fraud, a practice in which the manufacturer substitutes part or all of a product with an inferior, cheaper ingredient and then passes off the fake product as the real thing but at a lower cost. Varro Tyler, Ph.D., Sc.D., a distinguished professor emeritus of pharmacognosy (the study of medicinal products in their crude, or unprepared, form) at Purdue University in West LaFayette, Ind., advises consumers to avoid products sold for considerably less money than competing brands. "If it's too cheap, the product is probably not what it's supposed to be," he says.

Poor manufacturing practices are not unique to dietary supplements, but the growing market for supplements in a less restrictive regulatory environment creates the potential for supplements to be prone to quality-control problems. For example, FDA has identified several problems where some manufacturers were buying herbs, plants and other ingredients without first adequately testing them to determine whether the product they ordered was actually what they received or whether the ingredients were free from contaminants.

To help protect themselves, consumers should:

Consumers who use dietary supplements should always read product labels, follow directions, and heed all warnings.

Supplement users who suffer a serious harmful effect or illness that they think is related to supplement use should call a doctor or other health-care provider. He or she in turn can report it to FDA MedWatch by calling 1-800-FDA-1088 or going to www.fda.gov/medwatch/report/hcp.htm on the MedWatch Website. Patients' names are kept confidential.

Consumers also may call the toll-free MedWatch number or go to www.fda.gov/medwatch/report/consumer/consumer.htm on the MedWatch Website to report an adverse reaction. To file a report, consumers will be asked to provide:

Consumers also should report the problem to the manufacturer or distributor listed on the product's label and to the store where the product was bought.

The report of the President's Commission on Dietary Supplement Labels, released in November 1997, provides a look at the future of dietary supplements. It encourages researchers to find out whether consumers want and can use the information allowed in dietary supplement labeling under DSHEA. It encourages studies to identify more clearly the relationships between dietary supplements and health maintenance and disease prevention. It urges FDA to take enforcement action when questions about a product's safety arise. And it suggests that FDA and the industry work together to develop guidelines on the use of warning statements on dietary supplement labels.

FDA generally concurred with the commission's recommendations in the agency's 1998 proposed rule on dietary supplement claims.

While much remains unknown about many dietary supplements--their health benefits and potential risks, for example--there's one thing consumers can count on: the availability of a wide range of such products. But consumers who decide to take advantage of the expanding market should do so with care, making sure they have the necessary information and consulting with their doctors and other health professionals as needed.

"The majority of supplement manufacturers are responsible and careful," FDA's Yetley says. "But, as with all products on the market, consumers need to be discriminating. FDA and industry have important roles to play, but consumers must take responsibility, too."