Mil Med. 2019 Mar 1;184(Suppl 1):498-505. doi: 10.1093/milmed/usy393.
McCarthy MS1, Elshaw EB2, Szekely BM2, Raju D3.
Responses to constant dosing do not plateau in many people until >3 months
Study did manage to document trends at just 3 months
Probably would have had statistical significance (not just trends) if either:
- Had started with a loading dose
- Had the trial last 6 months
Average Vitamin D 23 ng ==> 35 ng
Note that 42% of the active duty soldiers were non-white,
Non-whites would likely have had low levels to start
Would have needed more than 5,000 IUs
Report of the study to the military - Aug 2019
Download the PDF from VitaminDWiki
- Soldiers need vitamin D, but levels cut in half in 18 years – March 2014
- Trial starting for Vitamin D with US soldiers – 2,000 and 5,000 IU for 3 months – Nov 2016
- Previous publication about this RCT - many problems noted at the time
- Need for Routine Vitamin D Screening in Military Personnel – Sept 2016
- US Army learning about benefits of vitamin D to trauma – Dec 2013 talking with Dr. Matthews
- Huge increase in Vitamin D supplementation in the US military (2005-13) – Oct 2016
Many months for Vitamin D level response, and even more for the body to get the benefits
PURPOSE: To explore response to vitamin D supplementation in active duty (AD) warfighters and translate findings into evidence-based health policy.
BACKGROUND: Soldiers are at risk for musculoskeletal injuries and metabolic dysfunction that impact physical performance and military readiness; the link with low vitamin D status is unclear.
This prospective trial enrolled 152 soldiers; baseline 25 hydroxyvitamin (OH) D level determined assignment to a no-treatment control (CG) or treatment group (TG) receiving a vitamin D3 supplement for 90 days. Symptoms, diet, sun exposure, and blood biomarkers obtained at baseline (T1) and 3 months (T2).
Cohort was predominantly white (58%) with a significant difference in racial distribution for vitamin D status. Mean (SD) 25(OH)D levels were 37.8 (5.6) ng/mL, 22.2 (5.0) ng/mL, and 22.9 (4.7) ng/mL for the CG, low dose TG, and high-dose TG at T1, respectively. Following three months of treatment, one-way ANOVA indicated a statistically significant difference between groups (F5,246 = 44.37; p < 0.0001). Vitamin D intake was 44% of Recommended Dietary Allowance throughout the first phase of the trial. Patient-Reported Outcomes Measurement Information System scores improved in TG for fatigue and sleep, p < 0.01.
CONCLUSIONS: Vitamin D deficiency is widespread in AD soldiers. Clinicians must intervene early in preventable health conditions impacting warfighter performance and readiness and recommend appropriate self-care strategies.