Introduction: In the scenario of vitamin D deficiency, this incident is prevalent and with risks to public health in the world, reaching approximately 90% of individuals. Hypovitaminosis D can cause, mainly in the elderly, lower bone mineral density, fractures, muscle weakness, falls, and acute respiratory infection. Objective: To evaluate the main clinical results on vitamin D levels in the elderly, as well as to analyze which daily or weekly dose of vitamin D is most effective in the elderly in reducing the number of falls and fractures. Methods: The present study developed a systematic review, addressing randomized clinical studies, diverse clinical studies, systematic reviews, meta-analysis, and the latest international consensus, following the rules of PRISMA. Results and Conclusion: A total of 152 articles were found involving the dosage and the impact of vitamin D in the elderly. In total, 72 articles were evaluated in full and 30 were included. According to the main literary findings, vitamin D deficiency implies problems with mineralization and bone mineral density, causing fractures and an increase in the number of elderly falls. In this sense, SBEM recommends maintaining vitamin D concentrations above 30 ng/mL. Also, vitamin D deficiency points to the occurrence of neurological diseases such as cognitive decline, risk of Alzheimer's disease, and depression. In the current scenario of the pandemic, vitamin D points as an important modulator of the immune system, and its deficiency promotes the unregulated release of cytokines, leading to complications in patients with COVID-19.