Vitamin D and its molecular targets in neurodegenerative diseases: a comprehensive review and potential therapeutic implications

Neurodegenerative disorders are regarded as the second leading cause of mortality in the current world, causing cognitive decline and motor dysfunction, significantly reducing quality of life. Approximately 15% of individuals around the world suffer from some of these diseases. Current supportive and rehabilitation therapies impose a significant financial burden on patients. Therefore, implementing preventive health policies can greatly decrease the rising prevalence of these diseases. Factors like genetics, environment, and nutrition are involved in these disorders. Vitamin D, as a neurosteroid and nutritional element, may affect neural cell health and development, helping to prevent neurobehavioral diseases. The current review sheds light on molecular mechanisms of vitamin D, including antioxidative and antiapoptotic pathways, regulation of calcium homeostasis in neurons, immunomodulatory and neurogenic properties, and involvement in Alzheimer's disease (AD), Parkinson's disease (PD), Multiple Sclerosis (MS), and Amyotrophic Lateral Sclerosis (ALS). The manuscript highlights a potential therapeutic perspective that can facilitate the prevention and management of neurodegenerative diseases.