Quantity, Duration, Adherence, and Reasons for Dietary Supplement Use among Adults: Results from NHANES 2011–2018

Dietary supplement use is common among US adults. We aimed to investigate the quantity, duration, adherence, and reasons for supplement use in individuals who take supplements. Data from 2011 to 2018 from the National Health and Nutrition Examination Survey (NHANES) dataset were analyzed. Four cycles of data were combined to estimate these outcomes. Results are presented as overall group and by subgroups. All analyses were weighted to be nationally representative. The Taylor Series Linearization approach was used to generate variance estimates. A total of 12,529 participants were included. Over 70% of these individuals reported taking more than one unit of dietary supplements daily. Notably, approximately 40% had been taking supplements for more than five years and about 67% were highly adherent to at least one supplement. However, only 26.9% of these supplements were taken following a doctor’s recommendation. The primary reasons for dietary supplements intake included improving overall health (37.2%), maintaining health (34.7%), bone health (21.4%), and diet supplementation (20.3%). Our findings indicate that most participants proactively used multiple dietary supplements focused on self-managed health and prevention, with substantial dedication to long-term use and high adherence. Healthcare professionals should play a more active role in guiding such behaviors to optimize the health outcomes of dietary supplement users across the United States.