Vitamin D Status and Epstein Barr Virus Activation
Maintaining vitamin D status without sunlight exposure is difficult without supplementation. This study was designed to better understand interrelationships between periodic vitamin D supplementation and immune function in Antarctic workers. The effect of 2 oral dosing regimens of vitamin D supplementation on vitamin D status and markers of immune function was evaluated in people in Antarctica with no UV light exposure for 6 mo. Participants were given a 2000-IU (50 μg) daily (n = 15) or 10,000-IU (250 μg) weekly (n = 14) vitamin D supplement for 6 mo during a winter in Antarctica. Biological samples were collected at baseline and at 3 and 6 mo. Vitamin D intake, markers of vitamin D and bone metabolism, and latent virus reactivation were determined. After 6 mo, the serum 25-hydroxyvitamin D concentration (mean ± SD) increased from 56 ± 17 to 79 ± 16 nmol/L and from 52 ± 10 to 69 ± 9 nmol/L in the 2000-IU/d and 10,000-IU/wk groups, respectively (main effect over time, P < 0.001). Participants with a greater BMI (participant BMI range = 19–43 g/m2) had a smaller increase in 25-hydroxyvitamin D after 6-mo supplementation (P < 0.05). Participants with high serum cortisol and higher serum 25-hydroxyvitamin D were less likely to shed Epstein-Barr virus in saliva (P < 0.05). The doses given raised vitamin D status in participants not exposed to sunlight for 6 mo, and the efficacy was influenced by baseline vitamin D status and BMI. The data also provide evidence that vitamin D, interacting with stress, can reduce risk of latent virus reactivation during the winter in Antarctica.
Sara R. Zwart, Satish K. Mehta, Robert Ploutz-Snyder, YaVonne Bourbeau, James P. Locke, Duane L. Pierson, and Scott M. Smith. Response to Vitamin D Supplementation during Antarctic Winter Is Related to BMI, and Supplementation Can Mitigate Epstein-Barr Virus Reactivation The Journal of Nutrition 2011 April Universities Space Research Association, Houston, TX 77058.