The increasing prevalence of nutritional supplement use in the United States, combined with the risk of adverse effects from these largely unregulated products, poses a significant challenge to health care professionals. The purpose of our study is to evaluate the use of nutritional supplements in an active duty military population, particularly those supplements with increased adverse effect profiles, and the sources of information that service members use to make decisions regarding the safety and efficacy of supplements. The investigators distributed a voluntary, anonymous, self-report survey to a battalion of active duty service members to collect demographic data and information pertaining to the use of, adverse effects from, and sources of information utilized regarding the safety and efficacy of nutritional supplements. Statistical analysis utilized Fisher's exact test for categorical variables and Kruskal-Wallis test for numeric variables via SAS 9.4 (SAS Institute Inc., Cary, NC, USA). The Henry Ford Health System Institutional Review Board evaluated and approved the study. The battalion commander approved the study protocol before the distribution of the survey. Over 50% of respondents reported using high-risk nutritional supplements. Males were more likely to use high-risk supplements than females (54.3% vs. 28.1%; P = .0017). Non-Commissioned Officers were more likely to use high-risk supplements than Junior Enlisted soldiers (67.2% vs. 40.2%, P = .0037). Only 27% of respondents who used high-risk supplements utilized medical professionals as their source of knowledge regarding the safety and efficacy of supplements. Females were more likely than males to seek supplement information from medical professionals (28.1% vs. 10.6%; P = .0202). Company-Grade Officers were more likely to seek supplement information from medical professionals than Junior Enlisted soldiers (40.9% vs. 8.3%; P = .0018). There was no statistically significant difference found for the rate of high-risk supplement use and obtaining information from a medical professional (P = .6982). About 3% of respondents reported adverse or unintended effects of supplement use. The results of our study suggest that a minority of service members seek advice from medical professionals regarding nutritional supplements, women are more likely to do so than men, men may be more likely to use high-risk supplements than women, and Non-Commissioned Officers use high-risk supplements more often than Junior Enlisted. Limitations of this study include the voluntary self-report survey design, relatively small sample size, and single location. A larger, multicenter study would aid to alleviate these limitations in future studies. Numerous studies investigating nutritional supplement use and associated risks are present in the literature; however, the data comparing supplement use with sources of information regarding safety and efficacy are lacking.