VDR and melanoma: Calcitriol, the active form of vitamin D, exerts its effects primarily by binding to the nuclear receptor of vitamin D.(12) There still is no definition as to the real role of vitamin D in melanoma.(13) Some sudies reported that polymorphisms of VDR genes are associated to the occurrence of various types of cancer, including melanoma, and that the presence of this polymorphism such as Fokl, Taql, and apa1, could be a biological marker of susceptibility to skin cancer.(14,15)