The study of rickets led to the discovery of vitamin D, which is a fat-soluble steroid hormone, whose precursor is converted into active metabolites in the skin when subjects to ultraviolet light. Few foods are rich in vitamin D, with sensible exposure to sunlight being the main natural source for the production of this vitamin. Vitamin D is carried by vitamin D-Binding Protein (DBP) in the circulation and binds to host cells through the Vitamin D Receptor (VDR). Several diseases and conditions have been linked to vitamin D deficiency and insufficiency, including periodontal disease. Vitamin D insufficiency is highly prevalent worldwide. It negatively impacts bone growth and metabolism, and multiple aspects of the immune response, mainly through the regulation of anti-microbial peptides such as Cathelicidin and β-defensins. Low vitamin D levels have been linked to increased gingival inflammation, periodontal destruction, alveolar bone loss, and tooth loss. It can also possibly affect osseointegration, although it has been explored in clinical studies on dental implants to a lesser degree. It is currently unclear whether vitamin D gene polymorphisms constitute risk factors for periodontitis. Higher levels of vitamin D can favor nonsurgical and surgical periodontal treatment outcomes, which can be achieved through a combination of dietary changes, increased sunlight exposure, and supplementation. Serum levels of vitamin D should be In the skin, the precursor of vitamin 7-dehydrocholesterol (7-DHC) is converted into pre-vitamin D3 and vitamin D3 when exposed to UVB radiation. Diet and/or supplements are additional sources of vitamin D. From the skin and small intestine, vitamin D binds to vitamin D-binding protein (DBP) for transport to the liver via blood circulation. In the liver, vitamin D is converted into 25-hydroxyvitamin D (25(OH)D). In the kidneys, 25(OH)D is converted into 1,25(OH)2D, which is the active vitamin D metabolite responsible for its endocrine, autocrine, and paracrine functions.Autoimmune diseases, infectious diseases, type 2 diabetes, preeclampsia, hypertension, cardiovascular disease, oral diseases, neurological disease, osteoporosis, different types of cancer, and higher overall mortality have been associated with vitamin D deficiency [6,7]. Deficiency is generally defined as values of 25(OH)D below 30 ng/ml [2,8,9]. It constitutes a public health challenge, affecting approximately 1 billion people around the globe. Insufficiency or subclinical deficiency can affect upto 50% of the world population [10,11]. General factors that contribute to low vitamin D levels and include decreased dietary intake, limited exposure to sunlight, reduced endogenous synthesis due to certain diseases, and lower hepatic catabolism due to certain medications [12]. Older age, obesity, dark skin, and conditions that change fat metabolism constitute additional factors that affect vitamin D status. Severe deficiency leads to incomplete mineralization of osseous tissues, which manifests as rickets in children, and oste...