Vitamin D Utilization May Improve Military Performance: A Mini-Review

Abstract

Studies from different regions of the world show that vitamin D deficiency is a common problem across the globe, even in military personnel. Risk factors of this deficiency includes elderly and female population, higher geographical latitudes, winter season, darker skins, low sunlight exposure, diet, and lack of vitamin D supplementation /fortification, although the deficiency in areas with higher sun exposure also has been documented. 
We reviewed some of the clinical trials and observations regarding vitamin D deficiency and supplementation. It has been shown that vitamin D deficiency is associated with more acute respiratory tract infections and acute pharyngitis resulting in more days off from training, more bone stress fractures, poor physical performance, and increased risk for suicide.
Clinical trials that utilized supplemental vitamin D shows decreased incidence of stress fractures in female navy recruits, lower incidence of influenza A and lower risk of acute respiratory tract infections, and improved bone density during initial military training, although one systematic review found conflicting data in supplementation with vitamin D for the prevention of acute respiratory infection.
These data opens a window for supplementation with vitamin D in populated military bases to decrease rate of respiratory infection and to minimize stress fractures for better performances; doses used for these purposes ranges from 300 to 1200 IU per day. Further clinical trials of vitamin D supplementation or dietary fortification for these military purposes should be conducted to determine the optimum dose and duration.