Role of vitamin D3 in selected malignant neoplasms.

Vitamin D3 is a fat-soluble essential nutrient that affects multiple biologic functions in the organism through calcitriol and the vitamin D3 receptor. This review article focuses on the results of studies on the relationship between the level of vitamin D3 and cancer incidence or mortality, but also on the anticancer properties of vitamin D3 that support its significant role in the prevention, clinical course, and overall survival rates of selected cancers (colorectal, prostate, breast, ovarian, endometrial, bladder, and malignant melanoma). The mechanisms of vitamin D3 action involve, among others, polymorphism of vitamin D3 receptor, cell cycle, caspases, and cancer stem cells. The level of vitamin D3 has been also demonstrated to serve as a biomarker in some cancers, and high levels of vitamin D3 can be conducive to successful cancer therapy.