title: Response to vitamin D supplementation during Antarctic winter is related to BMI, and supplementation can mitigate Epstein-Barr Virus Reactivation.
abstract: 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.
authors.affiliation: Universities Space Research Association, Houston, TX 77058, USA.
authors.forename: Sara R
authors.initials: SR
authors.lastname: Zwart
authors.forename: Satish K
authors.initials: SK
authors.lastname: Mehta
authors.forename: Robert
authors.initials: R
authors.lastname: Ploutz-Snyder
authors.forename: YaVonne
authors.initials: Y
authors.lastname: Bourbeau
authors.forename: James P
authors.initials: JP
authors.lastname: Locke
authors.forename: Duane L
authors.initials: DL
authors.lastname: Pierson
authors.forename: Scott M
authors.initials: SM
authors.lastname: Smith
mesh_terms: D000328:Adult; D000864:Antarctic Regions; D015992:Body Mass Index; D019587:Dietary Supplements; D005260:Female; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D014775:Virus Activation; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D