What is a dietary supplement?
As defined by Congress in the Dietary Supplement Health and Education Act, which became law in 1994, a dietary supplement is a product (other than tobacco) that
- is intended to supplement the diet
- contains one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances) or their constituents
- is intended to be taken by mouth as a pill, capsule, tablet, or liquid
- is labeled on the front panel as being a dietary supplement
What is a new dietary ingredient?
A new dietary ingredient is a dietary ingredient that was not sold in the United States in a dietary supplement before October 15, 1994.
Are dietary supplements different from foods and drugs?
Although dietary supplements are regulated by the U.S. Food and Drug Administration (FDA) as foods, they are regulated differently from other foods and from drugs. Whether a product is classified as a dietary supplement, conventional food, or drug is based on its intended use. Most often, classification as a dietary supplement is determined by the information that the manufacturer provides on the product label or in accompanying literature, although many food and dietary supplement product labels do not include this information.
What claims can manufacturers make for dietary supplements and drugs?
The types of claims that can be made on the labels of dietary supplements and drugs differ. Drug manufacturers may claim that their product will diagnose, cure, mitigate, treat, or prevent a disease. Such claims may not legally be made for dietary supplements.
The label of a dietary supplement or food product may contain one of three types of claims:
- a health claim
- a nutrient content claim
- a structure/function claim
Health claims describe a relationship between a food, food component, or dietary supplement ingredient, and reducing risk of a disease or health-related condition.
Nutrient content claims describe the relative amount of a nutrient or dietary substance in a product.
A structure/function claim is a statement describing how a product may affect the organs or systems of the body and it can not mention any specific disease. Structure/function claims do not require FDA approval but the manufacturer must provide FDA with the text of the claim within 30 days of putting the product on the market.
Product labels containing such claims must also include a disclaimer that reads, "This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease."
How does FDA regulate dietary supplements?
In addition to regulating label claims, FDA regulates dietary supplements in other ways. Supplement ingredients sold in the United States before October 15, 1994, are not required to be reviewed by FDA for their safety before they are marketed because they are presumed to be safe based on their history of use by humans.
For a new dietary ingredient-one not sold as a dietary supplement before 1994-the manufacturer must notify FDA of its intent to market a dietary supplement containing the new dietary ingredient and provide information on how it determined that reasonable evidence exists for safe human use of the product. FDA can either refuse to allow new ingredients into or remove existing ingredients from the marketplace for safety reasons.
Manufacturers do not have to provide FDA with evidence that dietary supplements are effective or safe; however, they are not permitted to market unsafe or ineffective products.
Once a dietary supplement is marketed, FDA has to prove that the product is not safe in order to restrict its use or remove it from the market. In contrast, before being allowed to market a drug product, manufacturers must obtain FDA approval by providing convincing evidence that it is both safe and effective.
The label of a dietary supplement product is required to be truthful and not misleading. If the label does not meet this requirement, FDA may remove the product from the marketplace or take other appropriate actions.
What methods are used to evaluate the health benefits and safety of a dietary supplement?
Scientists use several approaches to evaluate dietary supplements for their potential health benefits and safety risks, including their history of use and laboratory studies using cell or animal models.
Studies involving people (individual case reports, observational studies, and clinical trials) can provide information that is relevant to how dietary supplements are used. Researchers may conduct a systematic review to summarize and evaluate a group of clinical trials that meet certain criteria. A meta-analysis is a review that includes a statistical analysis of data combined from many studies.