Lichen planus is an autoimmune disease that can affect the skin and mucous membranes, including the oral mucosa (1). Vitamin D plays a very important role in the bone health along with boosting immunity. This study was carried out to assess the role of vitamin D in the treatment of oral lichen planus. A sample size of 450 was taken which included patients showing clinical presentation of oral lichen planus. The patients were equally divided into three different groups based on their vitamin D levels. The data were analyzed using SPSS version 26.0. The patients who were given the vitamin D supplementation showed the maximum improvement. The comparison of the data were found to be statistically significant. It was concluded that vitamin D played an important role in the treatment of oral lichen planus.