A review of 5 consecutive years of market research studies finds that supplement use by American adults is more common than previously reported by the National Health and Nutrition Examination Surveys.
The new research used data from online surveys conducted by the global market research company Ipsos Public Affairs for the Council for Responsible Nutrition (CRN), a Washington, DC-based trade association of the US supplement industry.
First and corresponding author Dr. Annette Dickinson, a consultant for CRN, says while the the National Health and Nutrition Examination Surveys (NHANES) data is invaluable, it only asks people questions about supplements taken in the last 30 days, whereas:
"The CRN/Ipsos data included regular, occasional and seasonal use throughout the year, which more realistically captures the full scope of dietary supplement utilization."
She and her colleagues report their findings in the Journal of the American College of Nutrition.
Surveys cover year-round supplement use and health behaviors
The data they reviewed came from CRN surveys carried out by Ipsos between 2007 and 2011. The surveys, which have been running since 2000, are completed online by about 2,000 US adults every year.
For their analysis, the researchers looked at prevalence of dietary supplement use for the 5 years. Also, for the year 2011, they looked in more detail at the reasons respondents gave for using supplements, plus some other details they gave about health behavior linked to supplement use. The results showed that:
People using dietary supplements are more likely than non-users to adopt a range of healthy behaviors.
- The percentage of respondents who had used supplements fluctuated between 64-69% over the 5 years
- Regular supplement use ranged from 48-53% - which is closer to that reported by NHANES
- When regular users were asked if they took a variety of supplements or just a multivitamin, the proportion who said they used a variety went up over the 5-year period (from 28-36%), while the proportion who said they just took a multivitamin fell (from 24-17%)
- The main reason respondents gave for using dietary supplements were for "overall health and wellness," and "to fill nutrient gaps in the diet."
The surveys also suggest people using dietary supplements are more likely than non-users to adopt a range of healthy behaviors, including exercising regularly, eating a balanced diet, visiting their doctor regularly, getting a good night's sleep and keeping to a healthy weight. This is in line with findings of previous studies, say the researchers.
Study suggests supplement use is 'mainstream' practice
The team says that the study makes an important point about supplement usage. Co-author and senior vice president for communications at CRN, Judy Blatman, explains:
"What the data tells us is that dietary supplement usage is a mainstream practice, and, contrary to some assertions, supplement users do not use these products as a license to slack off on eating right or exercising, but instead are health conscious individuals trying to do all the right things to be healthy."
"The evidence suggests that supplement use is viewed as one component of an overall wellness strategy," adds Dr. Dickinson.
The study comes in the wake of a heated debate sparked in December 2013, when the Annals of Internal Medicine published three studies examining whether routine use of vitamin and mineral supplements brought health benefits.
In the editorial of that issue, a group of medical experts concluded that multivitamins are a "waste of money" because in the main they do not prevent chronic disease or death, and there is evidence they may even do harm to well- nourished adults.