Dietary Supplements

Dietary Supplements

The demand for dietary supplements in the United States catapulted what was once a cottage industry into a $14 billion per year business in the year 2000. In 1994, the U.S. Congress formally defined the term dietary supplement as a product taken by mouth that contains a "dietary ingredient" intended to supplement the diet. The dietary ingredients in these products may include vitamins, minerals, herbs, amino acids, enzymes, organ tissues, glandulars, and metabolites. Dietary supplements can also be extracts or concentrates, and may be found in many forms, such as tablets, capsules, liquids, or powders.

The use of dietary supplements is widespread—they are taken by half of American adults. But the use of supplements is not limited to adults. A study published in the November 2001 Journal of the American Dietetic Association showed that dietary supplement use is prevalent among students as well, with 17.6 percent of 1,532 eighth-graders reporting the use of a vitamin-mineral supplement. Herbs, one type of dietary supplement, are widely used throughout the world. In China, traditional medicine encompasses a holistic approach to healing, and herbal remedies are routinely included in self-care. The World Health Organization (WHO) estimates that in developing countries up to 80 percent of indigenous populations rely on herbs for primary health care needs. In France and Germany, 30 to 40 percent of all medical doctors rely on herbal preparations as their primary medicines.

Regulation of Dietary Supplements

In 1994 the U.S. Congress passed the Dietary Supplement Health and Education Act (DSHEA), which President Bill Clinton signed into law the same year. One provision of DSHEA clarified the definition for dietary supplements outlined above. DSHEA also mandated the establishment of the Office of Dietary Supplements (ODS) within the National Institutes of Health. The ODS coordinates research on dietary supplements and acts as a clearinghouse for regulatory issues. It also maintains an excellent resource for consumers, the International Bibliographic Information on Dietary Supplements (IBIDS), which is a database that contains citations published in scientific journals on the topic of dietary supplements. The public can access IBIDS on the ODS website.

DSHEA established a new regulatory framework for supplement safety and for the labeling of dietary supplements by the U.S. Food and Drug Administration (FDA). Dietary supplements are regulated under food law, but with certain provisions that apply only to dietary supplements. For example, dietary supplements escape the stringent approval process that food additives and drugs must go through before being marketed to the public, unless the manufacturer of a dietary supplement makes a claim for therapeutic efficacy.

DSHEA also gave manufacturers the freedom to provide information about product benefits on labels through three types of claims. Health claims describe a relationship between a food substance and a disease or health-related condition. For example, the health claim "diets high in calcium may reduce the risk of osteoporosis" has been authorized by the FDA and may appear on the labels of dietary supplements. Structure function claims may state a benefit related to a nutrient-deficiency disease (such as scurvy, which is caused by a deficiency of vitamin C), as long as the statement tells how widespread the disease is. These claims may also describe the role of a nutrient intended to affect a structure or function—for example, "antioxidants maintain cell integrity," or "calcium builds strong bones." Nutrient content claims describe the level of a nutrient or dietary substance in a product, using FDA-regulated terms such as "good source," "high," or "free." For example, if a label claims a dietary supplement is fat-free, the supplement must contain less than 0.5 grams of fat per serving.

However, information on supplement labels cannot be false or misleading. For example, statements that a product will treat, cure, or diagnose a disease are reserved for drugs. That is why the label of the popular herbal extract echinacea may boast that the herb "supports good immune function" but will not claim to "cure your cold."

In Germany, herbs and herbal products are regulated in a different way than in the United States. In 1978, the German Federal Health Agency established the German Commission E to investigate the safety and efficacy of herbal remedies commonly used in Germany. The commission weighed evidence from the literature, from anecdotal reports, and from clinical studies. They subsequently developed monographs on over 400 herbs. These monographs are now used worldwide as essential references on herbal therapy. The commission also established indications (how an herb is used medicinally) and dosage recommendations, resulting in the successful mainstreaming of herbs into medical practice. German physicians frequently prescribe the herbs ginkgo biloba, hawthorn, St. John's wort, horse chestnut, and saw palmetto. Unlike U.S. law, German law allows herb manufacturers to market herbs with drug claims if the herb is proven safe and effective.

Controversies Surrounding the Use of Dietary Supplements

Opponents of DSHEA claim that the issue of public safety is their primary concern. Steven H. Zeisel, of the University of North Carolina School of Public Health and School of Medicine, writes that "DSHEA modifies the regulatory environment so that it becomes possible, even likely, that products will be marketed that inadvertently harm people" (Zeisel, p. 1855). Zeisel believes that the DSHEA legislation makes it easy for small enterprises to market products without investing the time and money needed to prove their product's safety and efficacy. He contrasts the development of a new dietary supplement to that of a new drug or food additive, for which there is a formal process to evaluate safety.

A manufacturer developing a new drug or food additive must conduct safety studies following FDA procedures. Results must be submitted to the FDA for review and approval before the ingredient or drug can be sold to the public. This is not the case for dietary supplements, however, because under DSHEA they are legally in a class by themselves. The FDA must simply be notified of the new product, and the notification must provide information that supports the manufacturer's claim that its product is safe. Once the product is marketed, the FDA is responsible for proving that a dietary supplement is unsafe before it can take action to restrict that product's use or remove it from the marketplace.

Another issue critics of DSHEA cite is the scant quality control of dietary supplements. Quality control is important to assure consumers that a product contains the ingredients stated on the label in the stated amounts. Neither the FDA nor any other federal or state agency routinely tests dietary supplements for quality prior to sale. But some manufacturers of dietary supplements do adhere to Good Manufacturing Practices (GMPs) and make every effort to produce a quality product. Also, the FDA has assisted the industry by proposing GMPs that focus on ensuring the identity, purity, quality, strength, and composition of dietary supplements.

DSHEA supporters fear that increased regulation of dietary supplements will decrease access to beneficial products. National opinion surveys show that many supplement users feel so strongly about the potential health benefits of supplements that they would continue to use them even if the supplements were shown to be ineffective in clinical studies. Consumers value freedom of choice, and many view regulation as an attempt by the government and medical establishment to monopolize treatment options. Clearly, a balance needs to be reached between preserving freedom of choice and ensuring that dietary supplements are safe and effective.

SEE ALSO ALTERNATIVE MEDICINES AND THERAPIES; FOOD LABELS; HEALTH CLAIMS; QUACKERY; VITAMINS, FAT-SOLUBLE; VITAMINS, WATER-SOLUBLE.

Jackie Shank

Bibliography

Blendon, R. J.; DesRoches, C. M.; Benson, J. M.; Brodie, M.; and Altman, D. E. (2001). "American's Views on the Use and Regulation of Dietary Supplements." Archives of Internal Medicine 161(6):805–10.

Dwyer, Johanna T.; Garceau, Anne O.; Evans, Marguerite; Li, Donglin; Lytle, Leslie; Hoelscher, Deanna; Nicklas, Theresa A.; and Zive, Michelle (2001). "Do Adolescent Vitamin-Mineral Supplement Users Have Better Nutrient Intakes than Nonusers? Observations from the CATCH Tracking Study." Journal of the American Dietetic Association 101(11):1340–1346.

Fleming, Thomas, ed. (1998). PDR for Herbal Medicines. Montvale, NJ: Medical Economics.

Sarubin, Allison (2000). The Health Professional's Guide to Popular Dietary Supplements. Chicago: American Dietetic Association.

Skidmore-Roth, Linda (2001). Mosby's Handbook of Herbs & Natural Supplements. St. Louis, MO: Mosby.

Somer, Elizabeth (1996). The Essential Guide to Vitamins and Minerals, 2nd edition. New York: HarperPerennial.

Zeisel, Steven H. (1999). "Regulation of Nutraceuticals." Science 285:1853–55.

Internet Resources

National Institutes of Health, Office of Dietary Supplements. <http://ods.od.nih.gov>

U.S. Food and Drug Administration Center for Food Safety and Applied Nutrition (2001). "Overview of Dietary Supplements." Available from <http://www.cfsan.fda.gov/~dms>