Vitamin D is currently recognized not only for its skeletal effects but also for its broader physiological influence, hence presenting a compelling subject for research. With its prevalence in global health discussions, vitamin D deficiency remains a multifaceted concern due to multiple factors like sunlight exposure, dietary insufficiencies, and various medical conditions. Despite its widespread occurrence, detection of deficiency remains challenging due to vague symptoms and limited routine screening. This deficiency poses a significant risk to bone health, affecting bone density and remodelling and potentially compromising the success of dental implants' osseointegration. Regarding dental implants, optimal vitamin D levels are pivotal for fostering osseointegration, yet questions persist: What serum levels should be achieved preoperatively, and how should deficient levels be restored?

Emerging evidence also highlights the link between vitamin D deficiency and head and neck cancer (HNC) pathogenesis. With its anti-proliferative and anti-inflammatory properties, vitamin D emerges as a promising adjunctive therapy in HNC management. Moreover, could vitamin D deficiency exacerbate bone metastasis and tumor-induced osteolysis in HNC patients? Addressing these questions mandates a meticulous and personalized approach to vitamin D supplementation, considering recommended doses, regimens, and forms. Highlighting the interplay of vitamin D in bone physiology, particularly concerning dental implants and HNC, while emphasizing the need for tailored preoperative management strategies and proactive screening in clinical practice.