A review of the neuroprotective role of vitamin D in traumatic brain injury with implications for supplementation post-concussion.

BACKGROUND: Nutritional interventions are promising treatment adjuncts in the management of concussion. Vitamin D (VDH) supplementation has demonstrated neuroprotective properties in multiple models of acquired brain injury.

OBJECTIVE: Review the neuroprotective role of VDH supplementation following traumatic brain injury (TBI).

METHODS: A Medline search was conducted to review manuscripts investigating the influence of VDH status or supplementation on TBI outcomes.

RESULTS: The search identified 165 studies, of which five were included. Four manuscripts studied a rodent model of TBI, while one studied a clinical sample. Vitamin D monotherapy independently reduced inflammation and neuronal injury following TBI, with a more robust effect observed in combination with progesterone (PROG). One study demonstrated VDH deficiency exacerbates post-TBI inflammatory response. One study in a clinical sample found combination therapy superior to PROG alone or placebo in improving outcomes after severe TBI. One study observed a more robust response to low-dose VDH compared to high-dose VDH when given in combination with PROG.

CONCLUSION: A protective role for VDH and a vitamin D sufficient status was identified for numerous outcomes following TBI. However, VDH supplementation cannot be recommended at this time to improve outcomes following TBI.