The Role of Vitamin D in the Disease Stage of Parkinson's Patients

Parkinson's disease (PD) is a disorder of brain function that is pathologically characterized by degeneration of nerve cells in the brain, specifically the basal ganglia. Additionally, there is a loss of pigmentation in the substantia nigra, the presence of cytoplasmic inclusions called Lewy bodies, and a decrease in dopamine in the Substantia nigra Pars Compacta (SNC) and corpus striatum. Vitamin D may provide neuroprotection through the action of neurotrophic factors, which regulate neuronal growth, or through protection against cytotoxicity. In some studies, the synthesis of neurotrophic factors, including Neurotrophin 3 (NT3) and Glial Cell Line-derived Neurotrophic Factor (GDNF), was found to be upregulated by 1,25(OH)2D3. A number of studies have demonstrated a higher prevalence of vitamin D deficiency in individuals with Parkinson's disease (PD) compared to healthy controls. Following the discovery that Vitamin D Receptor (VDR) and 1α-hydroxylase, an enzyme responsible for converting vitamin D into its active form, are highly expressed in the substantia nigra, it was postulated that insufficient circulating vitamin D may contribute to the dysfunction or cell death observed in this region. Keywords: Parkinson Disease, Substantia Nigra Pars Compacta, Glial Cell Line-derived Neurotrophic Factor, Vitamin D Receptor