Government and Legislation

Dietary Supplements and Labeling: What’s in That Bottle?

January 11, 2017   /

Use of dietary supplements has skyrocketed in the past few years, and today dietary supplements are used by more than half of the adult population in the United States. Specific vitamin supplements have clear benefits among certain population groups, but most studies do not provide strong evidence for the beneficial health-related effects of supplements taken singly, in pairs, or in combinations of three or more by the general population.

Supplements and herbs are recommended by health professionals, including registered dietitians. However, before dietitians routinely recommend vitamin supplements, it is important that they have a good understanding of supplement labeling and regulations.

In October 1994, the Dietary Supplement Health and Education Act (DSHEA) was signed into law. This law provided a new regulatory framework for the safety and labeling of dietary supplements. Under DSHEA, supplements are regulated as foods rather than medications. As a result of this law, manufacturers are responsible for determining that the products they produce are safe and that no false or misleading claims are made about their products.

Unlike prescription medications, dietary supplements do not need approval from the US Food and Drug Administration (FDA) before they are marketed and sold, unless they contain a new dietary ingredient. The FDA does not evaluate supplements for safety or effectiveness before they are marketed. Like food, the FDA sets specific guidelines for dietary supplement health claims.

On June 22, 2007, the FDA announced a final rule establishing current good manufacturing practice requirements (CGMPs) for dietary supplements. According to the rule, industry is required to evaluate the identity, purity, quality, strength, and composition of dietary supplements, and report all serious dietary supplement adverse events to the FDA. While the FDA requires that specific information appears on a supplement label, including a complete ingredient list, the net contents of the product, and a Supplements Facts label, this rule does not change the FDA’s role in supplement labeling. The CGMPs outline specific guidelines regarding manufacturing processes. However, the responsibility for compliance remains on the manufacturers, not the FDA.

A nongovernmental, nonprofit organization called the United States Pharmacopeia (USP) does verify dietary supplements, but participation in this program is voluntary. Supplements that participate in this program have a  “USP Verified” label.

USP verification assures that:

  • The ingredients on the label are in the bottle
  • The supplement is not contaminated
  • The body is able to digest the supplement
  • The supplement is made using good manufacturing practices

A list of companies that voluntarily participate in USP verification is found at

Risks are associated with vitamin supplements because of the lack of regulation by the FDA. For example, some supplements and botanicals contain more or less of an ingredient than is advertised. Sometimes substances that are not listed on the label are found in supplements, and not all supplements dissolve when ingested. In addition, it is estimated that less than 1% of adverse events associated with dietary supplements are reported to the FDA.

The widespread fortification of foods with vitamins and minerals, along with the additional use of dietary supplements, could result in an intake considerably above the recommended upper level of a nutrient. An example of negative effects from oversupplementation is the potential masking of B12 deficiency, because of high intake of folic acid from foods and supplements. Excessive intake of some nutrients from food and supplements could result in nutrient/medication interactions. Supplements with a dose or ingredients that are not accurately represented on the label may confound these potential complications.

Implications for dietetics practitioners
While most professionals agree that a daily multivitamin is safe for the general population, dietary supplements of one or more nutrients are associated with adverse events. Before recommending vitamin or herbal supplements, dietitians should carefully evaluate a patient’s intake of fortified foods, supplements, and herbs, and use evidence-based practice to recommend supplements, if they are indicated. Dietitians should evaluate patients for possible drug/nutrient interactions and potential overingestion of specific nutrients.

If dietitians recommend supplements for treatment of a specific condition, such as omega-3 fatty acids for heart disease, niacin for elevated cholesterol levels, or prenatal vitamins, they should recommend prescription-grade supplements to assure safety and efficacy of the medication.

Most consumers are unaware that dietary supplements are regulated as a food, instead of a prescription medication. If dietitians choose to recommend vitamin supplements to their patients, they should inform patients that supplements are not tested for dose, safety, or efficacy unless the manufacturer voluntarily participates in USP verification.


References and recommended readings
MedlinePlus. All herbs and supplements. Available at: Accessed August 26, 2012.

National Institutes of Health. NIH State-of-the-Science Conference: multivitamin/mineral supplements and chronic disease prevention: Available at: Accessed August 26, 2012.

National Institutes of Health, National Center for Complementary and Alternative Medicine. Health information: dietary supplements. Available at:*&proxyreload=1&x=0&y=0. Accessed August 26, 2012. 

National Institutes of Health, Office of Dietary Supplements. Making decisions. Available at: Accessed August 26, 2012.

US Dept of Health and Human Services, Food and Drug Administration. Current Good Manufacturing Practice in Manufacturing, Packaging, Labeling, or Holding Operations for Dietary Supplements. Federal Register. 2007;72:34752-34958. 21 CFR Part 111.Available at: Accessed August 26, 2012.

US Food and Drug Administration. Current good manufacturing practices (CGMPs): dietary supplements. Available at: Accessed August 26, 2012.

US Food and Drug Administration. Dietary supplement labeling guide. Available at: Accessed August 26, 2012.

US Food and Drug Administration. Overview of dietary supplements. Available at: Accessed August 26, 2012.

US Pharmacopeial Convention. USP verification services. Available at: Accessed August 26, 2012.