Postmenopausal women who take multivitamins appear to have the same risk of most common cancers, cardiovascular disease or dying of any cause as women who do not take multivitamin supplements, according to a report in the February 9 issue of Archives of Internal Medicine.
About half of Americans use dietary supplements, spending more than $20 billion per year on these products, according to background information in the article. "The motivations for supplement use vary, but common reasons include the belief that these preparations will prevent chronic diseases, such as cancer and cardiovascular disease," the authors write. "These views are often fueled by product health claims, consumer testimonials and an industry that is largely unregulated owing to the 1994 Dietary Supplement and Health Education Act." Scientific data supporting the benefits of supplements—including multivitamins, the most commonly used supplements—are lacking.
Marian L. Neuhouser, Ph.D., of the Fred Hutchinson Cancer Research Center, Seattle, and colleagues analyzed data from participants in the Women's Health Initiative (WHI): 161,808 women from three clinical trials testing hormone therapy, dietary modification and vitamin D supplements and 93,676 women who were part of an observational study. The women enrolled in the WHI between 1993 and 1998; information about vitamin use was collected through interviews and by supplement bottles brought to clinic visits.