Vitamin D3 potentiates myelination and recovery after facial nerve injury

Abstract

Roles of vitamin D on the immune and nervous systems are increasingly recognized. Two previous studies demonstrated that ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) induced functional recovery and increased myelination in a rat model of peroneal nerve transection. The current report assessed whether cholecalciferol was efficient in repairing transected rabbit facial nerves. Animals were randomized into two groups of rabbits with an unilateral facial nerve surgery: the vitamin D group included animals receiving a weekly oral bolus of vitamin D3 (200 IU/kg/day), from day 1 post-surgery; the control group included animals receiving a weekly oral bolus of vehicle (triglycerides). Contralateral unsectioned facial nerves from all experimental animals were used as controls for the histological study. The facial functional index was measured every week while the inner diameter of myelin sheath and the G ratio were quantified at the end of the 3 month experiment. The current report indicates that cholecalciferol significantly increases functional recovery and myelination, after 12 weeks of treatment. To the best of our knowledge, this is the first study investigating the therapeutic benefit of vitamin D supplementation in an animal model of facial paralysis. It paves further the way for clinical trials based on the administration of this steroid in individuals with injured facial nerves.

Electrophysiological evaluation of carpal tunnel syndrome female patients after vitamin D replacement

“…Our findings are similar to those from a study by Montava et al, in which facial nerve injury was induced in an experimental animal model. After 200 IU/kg/day oral vitamin D treatment, calcitriol induced functional recovery and myelination starting from the 6 th week, and myelination response was seen electrophysiologically starting from the 12 th week 7 . It has also been shown that in rat models with peroneal nerve injury, cholecalciferol and calcitriol induce peroneal nerve healing 8 .…”

“…Vitamin D is a steroid molecule and it is synthesized from 7-dehydrocholesterol by the action of ultraviolet B rays in the epidermis 6 . Experimental animal model studies demonstrated that vitamin D increases myelination after peripheral nerve injury and reduces neuronal injury 7,8 . Vitamin D deficiency may cause hyperinnervation and hypersensitivity in the nerve fibers and increases pain sensation and pain perception in the pathological process 9 .…”

“…Vitamin D3 and Vitamin D2, which accelerate the neuronal regeneration process, were approved by the FDA 7 . The role of calcitriol in treatment of the nervous system will be better understood if it is noted that the nervous system and ectoderm have a common embryologic origin 7 .…”

“…Vitamin D3 and Vitamin D2, which accelerate the neuronal regeneration process, were approved by the FDA 7 . The role of calcitriol in treatment of the nervous system will be better understood if it is noted that the nervous system and ectoderm have a common embryologic origin 7 . Therapeutic and protective effects of vitamin D are reduction in oxidative stress and provision of neuroplasticity and neuroprotection 10,11 .…”

Cholecalciferol (Vitamin D3) Reduces Rat Neuropathic Pain by Modulating Opioid Signaling

“…CYP27A1, CYP2J2 and CYP3A4 are potential players for the addition of a hydroxyl group on C25 of vitamin D, but CYP2R1 appears to be the most implicated enzyme in the conversion of cholecalciferol into 25 hydroxyvitamin D3 (25OHD3), or calcidiol (Cheng et al, 2003;Schuster, 2011). 25 (Holick, 2007). Within the whole body, calcitriol binds to the vitamin D receptor (VDR) and induces the transcription of hundreds of genes."…”