The NeuroVitD study aims to assess vitamin D levels in hospitalized cohorts with neurological disorders resulting in motor disabilities, providing epidemiological data necessary for guidelines. The primary objective is to assess vitamin D insufficiency in the neurological populations under investigation and secondary to evaluate the impact of vitamin D supplementation on problems associated with structural and functional parameters. The NeuroVitD study will be a randomized, cluster, controlled intervention trial lasting 2 years, enrolling 120 individulas, (30 controls), including those with stroke, spinal cord injury, and traumatic brain injury. Comprehensive epidemiological data, including demographic and anthropometric information, will be documented alongside social behaviors such as exercise and smoking. Serum vitamin D levels, bone density, body composition, strength, speed, physical performance and pain will be assessed. The study will also evaluate the effects of vitamin D supplementation at two distinct dosages: 50,000 I.U of vitamin D weekly for 8 weeks or 25,000 I.U of vitamin D for 4 weeks followed by 10,000 I.U of vitamin D drops weekly for an additional 4 weeks. Calcium, parathyroid hormone, and phosphorus levels will be assessed to examine the impact of vitamin D administration on additional biochemical markers. The findings will encompass vitamin D levels, bone density, body composition, strength, walking speed, physical performance and pain. The impact of vitamin D supplementation on various biochemical parameters will be analyzed, along with gender and group comparisons. Correlations will be established based on participants' residential locations, the administration of vitamin D supplementation, seasonal variations, and associations with specific medications for neurological conditions.