NIH Office of Dietary Supplements

What Does the NIH Office of Dietary Supplements Do?

The Office of Dietary Supplements was established by Congress in 1995 under the Dietary Supplement Health and Education Act (DSHEA). Housed within the National Institutes of Health, ODS does not regulate supplements — that is the role of the U.S. Food and Drug Administration — but it coordinates and supports research, evaluates scientific literature, and disseminates plain-language information about ingredients ranging from vitamin D and calcium to echinacea and ashwagandha.

ODS publishes two parallel sets of fact sheets: one written for consumers and one written for healthcare professionals. Each summarizes what an ingredient is, what evidence supports its use, recommended intakes where established, potential interactions with medications, and safety considerations. The office also maintains the Dietary Supplement Label Database (DSLD) and the Computer Access to Research on Dietary Supplements (CARDS) database, both used by researchers and clinicians worldwide.

Why Is Independent Supplement Guidance Important?

Under U.S. law, dietary supplements are regulated more like foods than pharmaceuticals. Manufacturers are responsible for ensuring their products are safe and accurately labeled, but they do not need FDA approval before placing a product on the market. This regulatory framework, combined with persuasive marketing, has contributed to a multibillion-dollar industry where consumer expectations often outpace the available evidence.

Independent guidance from ODS helps address this gap. For some nutrients — such as folic acid before and during early pregnancy, or vitamin B12 in people with deficiency — supplementation has clear, well-documented benefits. For many others, including most multivitamins taken by healthy adults, randomized trials have shown only modest or no benefits for outcomes such as cardiovascular disease or cancer prevention. ODS fact sheets present these findings in context, distinguishing populations who may genuinely benefit from those for whom routine supplementation is unlikely to add value.

How Should Consumers Use ODS Fact Sheets?

Healthcare providers and patients can use ODS resources as a first stop when evaluating whether a supplement is worth taking. Each fact sheet typically lists the Recommended Dietary Allowance (RDA) or Adequate Intake (AI) where defined by the National Academies, the Tolerable Upper Intake Level (UL) above which adverse effects become more likely, and notes on groups at risk of inadequacy, such as older adults for vitamin B12 or people with limited sun exposure for vitamin D.

Drug interactions are a particularly important section. St. John's wort, for example, can reduce the effectiveness of oral contraceptives, certain antidepressants, and some HIV medications. High-dose vitamin K can interfere with warfarin. ODS encourages consumers to disclose all supplements to clinicians and pharmacists, since polypharmacy combined with supplement use is increasingly common, especially among older adults who may take several products simultaneously.