More than half of adults in the United States are taking dietary supplements; however, use of multivitamins has reduced substantially, noted researchers based on a nationwide representative survey.
While earlier studies indicated an increase in the use of supplements between the 1980s and mid-2000s, researches carried out in recent years focused on health effects of dietary supplements and not their recent trends.
In order to understand the recent trends in dietary supplement use, Elizabeth D. Kantor and team from the Memorial Sloan Kettering Cancer Center in New York studied data from the National Health and Nutrition Examination Survey. The research was aimed at studying the trends in the usage of products including multivitamins, multiminerals, individual minerals, individual vitamins, and non-mineral and non-vitamin supplements among adults in the United States.
For the purpose of the study, the researchers included 37,958 adults with a mean age of 46 years, and of which 52 percent were women. Survey results show that use of dietary supplements among adults has remained stable between 1999 and 2012 and about 52 percent of participants used supplement products between 2011 and 2012.
However, the use of multivitamin and multimineral supplements, or MVMM, was observed to have reduced substantially in recent years. Between 1999 and 2000, 37 percent of people reported to have used MVMM supplements while only 31 percent of participants reported to have consumed MVMM supplements between 2011 and 2012.
It was also found that use of vitamin D supplements has increased from 5.1 percent to as high as 19 percent, and fish oil supplement use increased from as little as 1.3 percent to 12 percent. On the other hand, use of other supplements including selenium, vitamin C and E has decreased notably over the study period.
The researchers said that it is evident from the study findings that the use of dietary supplements among adults in the United States has stabilized over the years.
"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 researchers said.
The study results have clearly indicated that more than half of the adults in the country use dietary supplements, said researcher Dr. Pieter A. Cohen in an accompanying editorial. It is the responsibility of the physicians to advise people when to include supplements while reviewing medication. Doctors should also advise patients to avoid taking supplements if adverse effects are suspected.
"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," Cohen wrote.
The study published in JAMA was funded by the National Cancer Institute of the National Institutes of Health.
