Background: Vitamin D is obtained through food and nutritional supplements, or is synthesized in the skin by sunshine. It is then transferred to the liver and kidney through the bloodstream and hydroxylated by a specific enzyme (cytochrome P450 family 27 subfamilies A member 1, cytochrome P450 family 27 subfamily B member 1) to form 25-hydroxyvitamin D and 1,25-dihydroxy vitamin D. The vitamin D synthesis facilitates calcium and phosphorus absorption from the intestines. The parathyroid hormone helps to synthesize 1,25-dihydroxy vitamin D to aid calcium absorption. Objectives: Many researchers have investigated the relationship between serum vitamin D levels and periodontal disease. And periodontal disease indicators such as bleeding on probing, pocket depth, clinical attachment level, gingival index, and cementoenamel junction-alveolar cresthave been used to identify the effects of vitamin D on periodontal disease. The effects of vitamin D on bacteria or cytokines have also been investigated. In this review article, vitamin D levels according to the status of periodontal disease were summarized. Data sources: PubMed was searched electronically, and randomized clinical trials, cross-sectional studies, and case-control studies were included in the review. Study appraisal and synthesis methods: Articles that the classification of periodontitis was accurately described, indicators for identifying periodontitis was clearly marked, and the form of vitamin D measured in the study was accurately described were selected. Only highly relevant journals were selected and summarized. Results: Most of the research has found positive associations between the serum 25-hydroxyvitamin D level and periodontal health, and the clinical parameters of periodontal disease were reduced by vitamin D. Limitations: Detailed categorization of the characteristics associated with the 25-hydroxyvitamin D level should be needed in future studies. Conclusions: This review article can be used as a guide by clinicians and as a reference book for patients’ education.