By: Gloria Tsang, RD
Last Updated on:
Do you need to take dietary supplements every day? “That depends,” according to a panel of scientists.
New Report on Multivitamin Use
A panel of 13 experts met in Bethesda, Maryland, to assess the evidence available on multivitamin / mineral use and outcomes for disease prevention. They focused on review of randomized controlled trials (RCT). RCTs are often considered the gold standard for evidence-based public policy formulation. Convened by the National Institutes of Health (NIH), the panel released a draft statement on May 17, 2006.
Dietary supplements: Insufficient Evidence
Despite the widespread use of multivitamins, the panel found insufficient evidence to support a recommendation either for or against the use of multivitamins to prevent chronic diseases among healthy adults. However, the experts found evidence of use for specific single vitamin and/or mineral supplements and their combinations. Their findings are as follows:
- Beta-Carotene should be avoided by smokers due to an increased risk for lung cancer
- Calcium and Vitamin D benefit bone mineral density and prevent fracture risk in post-menopausal women
- More: Calcium Nutrition and Vitamin D and Osteoporosis
- Selenium may cut risk of prostate, lung and colorectal cancers
- Vitamin E may decrease deaths from heart disease in women; it may also lower the risk for prostate cancer in male smokers
- Antioxidants and Zinc: an antioxidant combination of vitamin C, vitamin E, beta-carotene and zinc may benefit intermediate age-related macular degeneration (AMD), a type of eye disease
The Bottom Line
As fortified foods are widely available nowadays, the panel cautioned that there is a risk of surpassing the upper tolerable level (UL) if people are taking a multivitamin or a single dietary supplement every day in addition to eating fortified foods. It is best to speak to your doctor or have a dietitian review your diet before taking dietary supplements.
Note: The NIH panel only reviewed evidence pertaining to the healthy adult population. Issues related to pregnant and lactating women, children or adults with chronic disease were not explored.

Gloria Tsang is the author of 5 books and the founder of HealthCastle.com, the largest online nutrition network run by registered dietitians. Her work has appeared in major national publications, and she is a regularly featured nutrition expert for media outlets across the country. The Huffington Post named her one of its Top 20 Nutrition Experts on Twitter. Gloria’s articles have appeared on various media such as Reuters, NBC & ABC affiliates, The Chicago Sun-Times, Reader’s Digest Canada, iVillage and USA Today.