vitamin d supplementation in warfighters

Conditions: Vitamin D Deficiency Disease

Summary: a genomics-based approach will target specific genes that may explain the response in biomarkers and symptoms before and after supplementation. one objective is to generate evidence-based recommendations for vitamin d supplementation in soldiers who often experience musculoskeletal disorders and immune dysfunction impacting physical performance and military readiness. the investigation is designed to address these specific aims: 1) explore vitamin d status in 105 service members to determine common symptoms associated with deficiency; 2) examine the effect of vitamin d levels on gene expression from select genes known to influence metabolism, bone density, and immune function; and 3) evaluate changes in gene expression between groups receiving high or low supplementation, and compare to healthy controls. follow-up at 15 months will evaluate circulating vitamin d.

a genomics-based approach will target identified candidate genes and search for variants that may explain the response observed in biomarkers and symptoms when deficient individuals are repleted. the long-term objective of this study is to translate findings from next-generation sequencing (ngs) technology into clinically meaningful data regarding vitamin d supplementation for service members (sm) who may be at risk for musculoskeletal disorders and immune dysfunction that impacts physical performance and military readiness. we propose the following specific aims: 1) explore the phenotypic expression of vitamin d status in a cohort of sm to determine common symptoms associated with deficiency/insufficiency states; 2) examine the effect of vitamin d levels on broad gene expression from carefully chosen candidate genes known to influence vitamin d status, bone density, and immune function; 3) evaluate changes in gene expression levels between and within groups supplemented with low vs high vitamin d, and compare to healthy controls, and 4) examine the relationship between vitamin d deficiency and the clinically relevant outcomes of stress fracture and high blood pressure before and after supplementation to a therapeutic plasma level of 25(oh)d. this prospective, randomized, double-blind trial will enroll 105 sm in the northwest to evaluate frequency, symptoms, and genomic expression of vitamin d levels using survey instruments, immunologic and bone biomarkers, and ngs of white blood cells pre- and post-supplementation with oral vitamin d over 3 months. participant follow-up at 12 months will evaluate maintenance of adequate circulating vitamin d; this timeframe represents a typical deployment period.

Eligibility criteria:
inclusion criteria: - active duty service member, age 18 years or older, ability to read and understand english, not deploying in the next 15 months, and subjectively in good health. exclusion criteria: - family members, beneficiaries, or civilians, pregnant or currently breastfeeding females, anyone with chronic health problems (e.g. eating disorders, kidney disease, liver disease, intestinal malabsorption), any active duty sm taking \>400 iu/day vitamin d supplementation and unwilling to discontinue this, current or healing stress fractures, taking medications for an endocrine disorder, such as synthroid, or those identified as having a high potential for interaction with vitamin d including anti-seizure medications, cyclosporine, and indinavir (crixivan).

Keywords: vitamin d deficiency, genomics, vitamin d supplementation