Vitamin D is a steroid hormone that is produced photochemicallyin epidermis. It is known that vitamin D involvedin the regulation of bone mineralization and calcium-phosphorus balance. However, in recent studies havesuggested that vitamin D may have a significant impactin the development of the cell proliferation, differentiation,neurotransmission, neuroplasticity, neurotropic andneuroprotective effects in central nervous system (CNS).For the reason of the effects, it can be considered as aneurosteroid was reported. It was discussed that the levelof vitamin D may be associated to neurodegenerativediseases such as Parkinson’s disease, Alzheimer’s disease,multiple sclerosis (MS), amyotrophic lateral sclerosis(ALS). The role of vitamin D and the mechanisms ofthese diseases will be discussed in the review. J Clin ExpInvest 2013; 4 (3): 411-415Key words: Vitamin D, neurosteroid, brain, neurologicdiseases