1α,25-Dihydroxyvitamin D3 reduces several types of UV-induced DNA damage and contributes to photoprotection

▸ We tested photoprotective effects of 1α,25-dihydroxivitamin D3 (1,25(OH)2D3) on several types of UV-induced DNA damage in human ex vivo skin. ▸ 1,25(OH)2D3 reduced UV-induced thymine dimers (TDs) in human ex vivo skin. ▸ 1,25(OH)2D3 reduced UV-induced 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) in human ex vivo skin. ▸ 1,25(OH)2D3 reduced UV-induced 8-nitroguanosine (8-NG) in human ex vivo skin. ▸ The mechanism of photoprotection by 1,25(OH)2D3 is likely to be through the reduction of reactive nitrogen species.