Self-reported dietary supplement use in deployed United States service members pre-deployment vs. during deployment, Afghanistan, 2013–2014

BACKGROUND: Dietary supplement use (protein/amino acids, weight-loss supplements, performance enhancers) is common among U.S. military members. Reported dietary supplement use in deployed troops is limited and is of concern in settings where troops are exposed to high ambient temperatures, increased physical demands, and dehydration. Our objective was to describe dietary supplement use and adverse events (AEs) among deployed U.S. service members compared with their pre-deployment use. METHODS: We conducted an institutional review board (IRB) approved, descriptive study in Afghanistan using a written questionnaire and collected demographic information, dietary supplement use before and during deployment, AEs associated with supplement use, and physical workout routines. Participants were U.S. military personnel of all branches of service deployed to Afghanistan. They were recruited in high-traffic areas in the combat theater. We analyzed the data with descriptive statistics. Paired t-test/Wilcoxon signed-rank test was conducted to examine the before/during deployment changes for continuous data, and McNemar’s chi-square test was conducted for categorical data. We constructed separate logistic regression models to determine the best predictors of increases or decreases in dietary supplement use, with demographic information, reasons for using supplements, and education requested/received as covariates in each model. All statistical tests were two-sided at a significance level of 5% (P < 0.05). RESULTS: Data were collected on 1685 participants. Ninety-seven of the participants were in the Army or Air Force. The participants were more likely to work out daily or more than once a day during deployment. Thirty-five percent of the participants reported no supplement use before or during deployment. The remaining 65% of participants reported increased use and increased frequency of use of supplements (e.g., daily) during deployment compared with pre-deployment. Additionally, more people followed label instructions strictly during deployment vs. pre-deployment. Overall, the frequency of self-reported AEs among supplement users remained consistent before and during deployment. The only significant difference noted was in problems falling or staying asleep, which increased during deployment. In the adjusted logistic regression models, the level of formal education, military branch, occupational specialty, education about dietary supplements, and certain reasons for using supplements (to boost energy, lose weight, gain muscle strength and mass, and as a meal replacement) were significant predictors of changes in supplement use. CONCLUSION: Deployed U.S. service members were more likely to use dietary supplements, use more than one supplement and use supplements more frequently during deployment than pre-deployment. No serious AEs were reported, but problems falling or staying asleep increased during deployment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40779-017-0141-6) contains supplementary material, which is available to authorized users.