Abstract Background Over 50% of adults currently use dietary supplements (DS) but manufacturers do not have to prove the safety or efficacy of a DS before it is marketed. Therefore, consumers may be exposed to inaccurate DS information, may lack confidence in choosing appropriate DS and may seek advice for usage. The objective of this study was to examine trends in usage, attitudes, and sources of information regarding DS according to geographic location, demographic group, and lifestyle choices. Methods Eligible individuals completed a 10-item researcher-developed survey tool to determine DS use, sources of DS information, and DS-related knowledge and attitudes over the previous year. Healthy participants (637 individuals aged 21–75 years) from two population-based cohorts that had been recruited for lipoprotein assessment studies at Tufts University in Boston, Massachusetts and University of California at Davis. Outcome measures included participants’ use, beliefs regarding essentiality of DS, confidence in choosing appropriate DS, and sources of information on DS. Univariate and multivariate logistic regression were utilized to examine differences in survey responses between groups. Results Of the total population 72.7% reported taking dietary supplements in the previous year. Those living on the West Coast (80.3%) had greater use than those living on the East Coast (60.7%). Those on the East Coast were more likely to believe DS were essential to health (48.7%) and to feel confident in choosing DS that were appropriate for them (51.0%). Overall, physicians were the most frequent source of DS information for more than 50% of participants on both coasts. Conclusion Because DS usage is widespread, health care providers and nutrition educators must encourage patients to discuss their DS use and be equipped to provide information conducive to safe, efficacious consumption. Tailoring interventions for healthcare providers, media sources, industry, and the public may allow for dissemination of up-to-date information regarding DS.