UV Radiation, Vitamin D, and Epidermal Carcinogenesis

The document discussed the dual role of UVB radiation in both producing vitamin D in the skin and causing nonmelanoma skin cancer (NMSC). While vitamin D has been shown to protect against various cancers, its protective effect against NMSC was less clear. However, recent studies indicated that animals without the vitamin D receptor were more likely to develop NMSC after exposure to UVR or chemical carcinogens. This suggested that vitamin D and its active form, 1,25-dihydroxyvitamin D3, might protect against NMSC by regulating the hedgehog and β-catenin pathways and enhancing the DNA damage response.