Trends in Dietary Supplement Use among US Adults From 1999–2012

Abstract

Importance

Dietary supplements are commonly used by US adults; yet, little is known about recent trends in supplement use.

Objective

To report trends in dietary supplement use among US adults.

Design, Setting, and Participants

Temporal trends in supplement use were evaluated using nationally representative data from the National Health and Nutrition Examination Survey (NHANES) collected between 1999 and 2012. Participants include non-institutionalized adults residing in the US, surveyed over 7 continuous 2-year cycles (sample size per cycle ranged from 4,863 to 6,213).

Exposures

Calendar time, as represented by NHANES cycle.

Main Outcomes/Measures

In an in-home interview, participants were queried on use of supplements in the 30 days prior. This information was used to estimate the prevalence of use within each NHANES cycle, and trends were evaluated across cycles. Results are presented for use of any supplements, use of multivitamins/multiminerals (MVMM), as defined by a product containing ≥10 vitamins and/or minerals, as well as use of individual vitamins, minerals, and non-vitamin, non-mineral supplements. Results are presented overall, and by population subgroup, including age, sex, race/ethnicity, and educational status. All analyses are weighted to be nationally representative.

Results

A total of 37,958 adults were included in the study [weighted mean age, 46.4 years, 52.0% women], with an overall response rate of 74%. Overall, use of supplements remained stable between 1999 and 2012, with 52% of US adults reporting use of any supplements in 2011–2012 (p-trend:0.19). This trend varied by population subgroup. Use of MVMM decreased, with 37% reporting use of MVMM in 1999–2000 and 31% reporting use in 2011–2012 (difference: −5.7%; 95% CI: −8.6%, −2.7%; p-trend<0.001). Vitamin D supplementation from sources other than MVMM increased from 5.1% to 19% (difference: 14%; 95% CI: 12%, 17%; p-trend<0.001) and use of fish oil supplements increased from 1.3% to 12% (difference: 11%; 95% CI: 9.1%, 12%; p-trend<0.001) over the study period, while use of a number of supplements decreased.

Conclusions and Relevance

Among adults in the United States, overall use of dietary supplements remained stable from 1999–2012, use of MVMM decreased, and trends in use of individual supplements varied and were heterogeneous by population subgroups.