Posted April 17, 2006
PANEL CALLS FOR EXPANDED OVERSIGHT OF VITAMIN AND MINERAL SUPPLEMENTS
An independent panel convened by the NIH Office of Medical
Applications of Research and the Office of Dietary Supplements in May 2006 assessed
the available evidence on the safety and effectiveness of
multivitamin/minerals (MVMs). Following two days of expert
presentations, public discussion, and panel deliberations, the panel
made recommendations regarding certain specific supplements but
ultimately concluded that more rigorous scientific research is needed
before strong recommendations can be made regarding MVM use to prevent
chronic diseases.
The panel released a draft statement of its finding at
the close of the conference. The panel's findings pertain to the
generally healthy population, and do not include pregnant women,
children, or those with disease. Full text of the panel's draft
state-of-the-science statement is available at
http://consensus.nih.gov. The final version will be available at the
same Web site in 4 to 6 weeks.
"Half of American adults are taking MVMs and the bottom line is that we
don't know for sure that they're benefiting from them. In fact, we're
concerned that some people may be getting too much of certain
nutrients," said J. Michael McGinnis, MD, MPP, senior scholar with
the Institute of Medicine of the National Academy of Sciences, who
chaired the panel.
The panel recommended the combined use of calcium and vitamin D
supplementation for postmenopausal women to protect bone health. The
panel also advocated that antioxidants and zinc be considered for use
by nonsmoking adults with early-stage, age-related macular
degeneration, an eye condition that can cause blindness. The panel
supports previous recommendations by the CDC that women of childbearing
age take daily folate to prevent neural tube defects in infants. Conversely, it found no evidence
to recommend beta carotene supplements, a form of vitamin A, for the
general population, and strong evidence to caution smokers against
taking them. Specifically, beta-carotene was linked to an increase in
lung cancer among smokers who took the vitamin regularly.
In looking specifically at MVMs for chronic disease prevention, however,
the panel found available data are insufficient to make a firm
recommendation for or against their use in the general population.
Of note, rates of MVM use are highest among those who engage in other
positive health behaviors such as regular exercise and eating a
healthier diet, making it difficult to determine whether the MVM alone
is truly responsible for any observed improvement in health.
Most of the public assumes that the components of MVM supplements are
safe, because many of the ingredients are found in everyday foods and
the products are available over-the-counter. The panel identified
several possible risks associated with MVM consumption, however. Among
these is the potential for overconsumption of certain nutrients, with
the resulting possibility of adverse effects. Though health-conscious
individuals are likely to be focused on ensuring that they meet the
recommendations for essential nutrients, the combined effects of eating
fortified foods, taking MVMs, and consuming single vitamins or minerals
in large doses, may lead them to unwittingly exceed the Upper Levels
(ULs) of nutrients, which can be harmful.
Given these safety concerns and the limitations of the available
evidence, the panel advocated for changes in the regulation of dietary
supplements -- including MVMs -- by the Food and Drug Administration
(FDA). Specifically, the panel recommends that Congress expand FDA's
authority and resources to require manufacturers to disclose adverse
events, to ensure quality production, and to facilitate consumer
reporting of adverse events by including reporting information on
dietary supplement labels.