Vitamin D: preventive and therapeutic potential in Parkinson's disease.

Vitamin D is one of the important nuclear steroid transcription regulators that controls transcriptions of a large number of genes. Vitamin D supplement is commonly recommended for the elderly to prevent bone diseases. Amounting new evidence has indicated that vitamin D plays a crucial role in brain development, brain function regulation and neuroprotection. Parkinson's disease (PD) is a degenerative disorder commonly seen in the elderly, characterized by movement disorders including tremor, akinesia, and loss of postural reflexes. The motor symptoms largely result from the continued death of dopaminergic neurons in the substantia nigra, despite use of current therapeutic interventions. The cause and mechanism of neuron death is currently unknown. Vitamin D deficiency is common in patients with PD suggesting its preventive and therapeutic potential. Vitamin D may exert protective and neurotropic effects directly at cellular level, e.g. protection of dopamine system, and/or by regulating gene expression. This review summarizes the epidemiological, genetic and translational evidence implicating vitamin D as a candidate for prevention and treatment for PD.