ABSTRACT BACKGROUND: Oral lichen planus (OLP) is known to be a chronic inflammatory disease associated with various other systemic disorders. Studies have shown that vitamin D deficiency can be involved in the pathogenesis of lichen planus. The aim of this study was to investigate the role of vitamin D and vitamin D receptor in OLP.METHODS: In this review study, all English and Persian articles were searched by relevant keywords from the Google scholar, PubMed, science direct, Cochrane, Scopus and Sid databases until January 2020.RESULTS: From the 16 articles obtained after reviewing the abstracts, finally 14 appropriate articles were included in this study.CONCLUSION: According to the results of the studies, vitamin D deficiency may be associated with an increased risk of OLP lesions.KEYWORDS: Oral lichen planus, Vitamin D, Vitamin D receptor