Dietary Supplement Use in Middle-aged and Older Adults.

OBJECTIVES: Despite limited evidence of clinical benefits, dietary supplement use is increasingly common among older adults. The aim of this study was to characterise the prevalence of dietary supplement use in a national sample of community-dwelling middle-aged and older adults and investigate factors associated with its use.

DESIGN/SETTING/PARTICIPANTS: This was a cross-sectional study using data from the Health and Retirement Study (HRS), a biennial, nationally representative survey of individuals aged 50 years and older in the United States. This study combined data from the 2013/14 Health Care and Nutrition Survey (HCNS) and 2012 Core Survey.

MEASUREMENTS: The primary outcome was the use of any dietary supplement at least once a week. Secondary outcomes were the use of multivitamins and specific vitamin and supplement types. Multivariable regression models were used to identify factors associated with any dietary supplement use.

RESULTS: A total of 6045 participants (weighted n = 71,268,015) were included in the final analytical sample (mean age 67.7 years, 59.3% female). Of these, 84.6% (n=60,292,704) were regular dietary supplement users, with participants taking a mean of 3.2±0.1 different dietary supplements and 41.9% taking four or more. Multivitamins were the most common, used by 57.5% (n=41,147,146) of participants. Other commonly used dietary supplements were vitamin D, fish oil, calcium, vitamin C, and vitamin B12. Older age (75+ years), female sex, higher education, daily alcohol use, vigorous physical activity, regular medication use, and arthritis were associated with higher odds of dietary supplement use.

CONCLUSIONS: In this sample of middle-aged and older Americans, more than 4 out of 5 used a dietary supplement. Certain demographic, behavioural, and clinical factors were associated with their use. Given the lack of evidence for improving health outcomes, our findings suggest potential overuse of dietary supplements in people over the age of 50.