Testosterone And Vitamin D Concentrations In Military Personnel Following Traumatic Brain Injury

Purpose: To investigate testosterone and vitamin D status in service members, with and without a history of traumatic brain injury (TBI). Methods: This retrospective de-identified medical review analyzed hormone assessments ordered for 4,285 active duty and veteran military personnel at Womack Army Medical Center, Fort Bragg, NC from 2016-2018. Results: Overall, 343 (8%) of service members had a medically diagnosed TBI. In all men, 19% were deficient in testosterone (<270 ng/dl), and 10% had a testosterone prescription. Active duty men with a history of TBI had lower testosterone compared to active duty men with no documented head injury, but there was no significant difference in veteran men. More than one-third (38%) of all service members were insufficient in vitamin D (<30 ng/ml). Overall there was a weak positive correlation between testosterone and vitamin D concentrations in men but not in women. Conclusions: Our research does not support evidence for high rates of hypogonadism, testosterone prescription, or vitamin D deficiency after TBI compared to military personnel without prior injury. However, our overall dataset shows a high prevalence of vitamin D insufficiency in service members independent of TBI, further supporting that vitamin D status should be assessed regularly in service members.