Vitamin D Supplementation in Warfighters
Study Details
Study Description
Brief 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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Detailed Description
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.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Active Comparator: Healthy control group Subjects in this arm have a normal serum level of 25(OH)D, >30 ng/mL. Subjects submit to blood draws and biometric tests (DXA, body composition, BP) and questionnaires on 3 occasions. They do not receive vitamin D3 supplementation. |
Dietary Supplement: Vitamin D3
As in Arms
Other Names:
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| Experimental: Low dose supplementation group Subjects in this group have been identified as having a level of 25(OH)D of < 30 ng/mL and are randomized to receive vitamin D3 supplementation of 2000 IU daily for 3 months. |
Dietary Supplement: Vitamin D3
As in Arms
Other Names:
|
| Experimental: High dose supplementation group Subjects in this group have been identified as having a level of 25(OH)D of <30 ng/mL and are randomized to receive vitamin D3 supplementation of 5000 IU daily for 3 months. |
Dietary Supplement: Vitamin D3
As in Arms
Other Names:
|
Outcome Measures
Primary Outcome Measures
- 25(OH)D [15 months]
Serum measure of 25(OH) at baseline, 3 months, and 15 months
Secondary Outcome Measures
- Vitamin D gene expression [3 months]
Gene expression analysis will be used to determine relationship between low and high dose vitamin D supplementation and 25(OH)D levels, blood pressure, bone density, and body fat
Eligibility Criteria
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).
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Madigan Army Medical Center | Tacoma | Washington | United States | 98431 |
Sponsors and Collaborators
- Madigan Army Medical Center
- TriService Nursing Research Program
Investigators
- Principal Investigator: Mary S McCarthy, PhD, Madigan Army Medical Center
Study Documents (Full-Text)
None provided.More Information
Publications
- Carlberg C. Genome-wide (over)view on the actions of vitamin D. Front Physiol. 2014 Apr 29;5:167. doi: 10.3389/fphys.2014.00167. eCollection 2014. Review.
- Fiscella K, Franks P. Vitamin D, race, and cardiovascular mortality: findings from a national US sample. Ann Fam Med. 2010 Jan-Feb;8(1):11-8. doi: 10.1370/afm.1035.
- Yanovich R, Friedman E, Milgrom R, Oberman B, Freedman L, Moran DS. Candidate gene analysis in israeli soldiers with stress fractures. J Sports Sci Med. 2012 Mar 1;11(1):147-55. eCollection 2012.
- HU001-15-1-TS05