Background: In general, the role of vitamin D, [25 (OH)D], is to regulate calcium and phosphate metabolism by bone remodeling but the studies, in the recent decades, shown that low exposure at the sun and vitamin D deficiency are associated with the increased risk of many other extra-skeletal disorders, such as cancer diseases.Content: Several original studies and meta-analyses have evaluated the role of vitamin D in cancer prevention or the potential to improve cancer treatment outcomes. The broad field of antitumor effects of calcitriol and analogues in the treatment of cancer, as single agents or in combination with other anticancer agents, is mainly based on the mechanisms of inhibition of cancer cell proliferation and invasiveness, induction of differentiation, apoptosis and the promotion of angiogenesis. Summary and Outlook:The scientific evidence suggests that the provider of health care should consider the increasing of concentrations of 25 (OH) D through sun exposure or by supplementing with vitamin D of people with different ages to reduce the risk ills with Vitamin D deficiency besides the standard treatment of some chronic diseases, inclusive cancer disease beside the specific personalized antineoplastic treatments for every malignant disease.