The importance of vitamin D in bone and phosphocalcic status is well recognized by the scientific and medical communities; however, recently identified properties of this cholesterol derived molecule, such as immunomodulator and anticancer activities, are discussed in this article (1). Actually, the debate is not so much about the new vitamin D properties, but rather about the optimal concentration required to reach these properties. The difficulty in determining the norms is rendered even more complex by the existence of a vitamin D receptor gene polymorphism. The body pool of this vitamin depends essentially on its endogenous synthesis, but also on its dietary intakes. Many epidemiological studies interested in Vitamin D serum level and cancer suggest a relation between low Vitamin D level and cancer risk, especially in breast and colon adenocarcinomas. In vitro, many studies showed, in different human and animal malignant cell lines, that this molecule exerts anticancer activities: it induces apoptosis and cell differentiation as well as it inhibits proliferation and angiogenesis. This review tries to update the current knowledge on vitamin D and, more particularly, the potential interest of this molecule in cancer prevention and management.