Multivitamin and Protein Supplement Use Is Associated With Positive Mood States and Health Behaviors in US Military and Coast Guard Personnel

Approximately 60% of Armed Forces personnel regularly consume dietary supplements (DSs). We investigated the association of mood and health behaviors with multiple classes of DSs in military and Coast Guard personnel (N = 5536). Participants completed a survey of DS use and the Quick Mood Scale to assess mood domains of wakeful-drowsiness, relaxed-anxious, cheerful-depressed, friendly-aggression, clearheaded-confused, and well coordinated-clumsy. Supplements were categorized as multivitamin/minerals (MVM), individual vitamin/minerals, protein/amino acid supplements (PS), combination products (C), herbals (H), purported steroid analogs, (S) and other (O). One-way analyses of covariance assessed associations of DSs and perceived health behavior with mood controlling for age. Logistic regression determined associations between DS use and health behavior. Users of MVM and PS reported feeling significantly (P < 0.05) more awake, relaxed, cheerful, clearheaded, and coordinated. Participants using PS and S reported feeling less friendly (more aggressive, P < 0.02). Users of MVM and PS were more likely to report their general health, eating habits, and fitness level as excellent/good (P < 0.05). Participants reporting health behaviors as excellent/good were more (P < 0.01) awake, relaxed, cheerful, friendly, clearheaded, and coordinated. As no known biological mechanisms can explain such diverse effects of MVM and PS use on multiple mood states, health, eating habits, and fitness, we hypothesize these associations are not causal, and DS intake does not alter these parameters per se. Preexisting differences in mood and other health-related behaviors and outcomes between users versus nonusers of DSs could be a confounding factor in studies of DSs.