The U.S. Preventive Services Task Force and the National Institutes of Health recommend against taking multivitamins to prevent chronic diseases. Yet millions of Americans continue to pop the pills. According to data from the National Health and Nutrition Examination Survey, about 30% of the American population are multivitamin users.
A meta-analysis published today in Circulation: Cardiovascular Quality and Outcomes added another brick in the wall of evidence that multivitamins have no cardiovascular benefits.
The meta-analysis included 18 prospective cohort studies and randomized trials, encompassing more two million participants and 18 million person-years of follow-up.
When the research team of investigators from Johns Hopkins and other universities combined all the data, they found no statistical associations between multivitamin supplements and CVD mortality, CHD mortality, stroke mortality, or stroke incidence.
They noted that multivitamin use is associated with lower risk of CHD incidence in studies done outside the United States while no benefit has been found by the studies performed in this country. They chalk up the discrepancy to unmeasured confounding rather than true regional differences.