Vitamin D is a secosteroid hormone that is partly synthesized in skin cells by the action of ultraviolet B sun rays (UVB), and is partly ingested through diet. In order to be activated, it must first undergo a process of hydroxylation through the liver and then again in the kidneys. This creates the active form of vitamin D, calcitriol, ie. 1,25-dihydroxycholecalciferol (1,25(OH)2D3). The activated vitamin binds to a special vitamin D receptor (VDR), and in this way achieves its biological effect. Vitamin D is mostly involved in the calcium and phosphate homeostasis, which plays a major role in the regulation of musculoskeletal health. Recently, in addition to its skeletal functions, importance has been given to the newly discovered functions of vitamin D. It has been shown that many cells that are not associated with calcium homeostasis also possess membrane receptors required for vitamin D activation. These include T and B lymphocytes, malignant cells, skin cells, as well as placenta, pancreas, prostate, and colon cells. In addition, its contribution to the regulation of cardiovascular health has been confirmed, as well as in the quality of the immune response, in wound healing and even in cancer prevention. Its most famous role is certainly to participate in bone remodeling. A large number of existing studies suggests a correlation between jaw bone mineral density (BMD) and individual parameters of systemic osteoporosis, suggesting that osteoporosis may be a risk factor for periodontal disease. Vitamin D deficiency has become an almost global epidemic that entails multiple chronic health problems, including cardiovascular and autoimmune diseases, hypertension, diabetes, and many different types of cancer. There is also evidence of correlation between serum vitamin D levels and increased gingival inflammation which supports the importance of vitamin D in periodontal health which will be discussed in more detail in this publication.