Use of Multivitamins Decreases in the United States

The use of supplements among US adults has remained stable from 1999 to 2012, shows a national representative survey. However, the use of multivitamins decreased during this period.

Dietary supplement products are commonly used by adults in the United States, with prior research indicating an increase in use between the 1980s and mid-2000s. Despite extensive research conducted on the role of dietary supplements in health, little is known about recent trends in supplement use. Elizabeth D. Kantor, Ph.D., of Memorial Sloan Kettering Cancer Center, New York, and colleagues used data from the National Health and Nutrition Examination Survey (NHANES) to examine trends in supplement use among U.S. adults from 1999 through 2012, with a focus on use of any supplement products and multivitamins/multimineral (MVMM; defined as a product containing 10 or more vitamins and/or minerals), as well as use of individual vitamins, minerals, and nonvitamin, nonmineral supplements. Participants were surveyed over 7 continuous 2-year cycles.

‘More than half of the adults in the United States use supplements. Most of the supplements contain pharmaceutically active botanicals, which can have adverse side effects.’

A total of 37,958 adults were included in the study (average age, 46 years; women, 52 percent), with a response rate of 74 percent. Overall, the use of supplements remained stable between 1999 and 2012, with 52 percent of U.S. adults reporting the use of any supplements in 2011-2012. Use of MVMM decreased, with 37 percent reporting use in 1999-2000 and 31 percent reporting use in 2011-2012. Vitamin D supplementation from sources other than MVMM increased from 5.1 percent to 19 percent and use of fish oil supplements increased from 1.3 percent to 12 percent over the study period, whereas use of a number of other supplements decreased, including vitamins C, E, and selenium.

Trends varied across age, sex, race/ethnicity, and education.

"With the present data, it is clear that the use of supplements among U.S. adults has stabilized. This stabilization appears to be the balance of several opposing trends, with a major contributing downward factor being the decrease in use of MVMM," the authors write.

"What are the conclusions from this new analysis? It is now well documented that more than half of U.S. adults use supplements. Physicians should include supplements when they review medications with all patients and also consider supplements when symptoms raise the possibility of a supplement-related adverse effect. It is now known that many supplements contain pharmaceutically active botanicals, which can have important clinical effects," writes Pieter A. Cohen, M.D., of the Cambridge Health Alliance, Cambridge, and Harvard Medical School, Boston, in an accompanying editorial.

"For example, red yeast rice, yohimbe, and caffeine all have pharmacological effects, and although ephedra has been banned, a variety of synthetic drugs have replaced ephedra as stimulants in many sports and weight loss supplements. Reporting suspected adverse effects of supplements is also critical. The FDA relies on physicians and consumers to report adverse events via MedWatch to remove hazardous supplements from the marketplace."

"The current study by Kantor et al should also lead funders and legislators to reconsider their priorities with respect to supplements. Given the current regulatory framework, even high-quality research appears to have only modest effects on supplement use. Future efforts should focus on developing regulatory reforms that provide consumers with accurate information about the efficacy and safety of supplements and on improving mechanisms for identifying products that are causing more harm than good."

The study is published in JAMA.

Source: Eurekalert