Hmu. Dm’s open Ignore

Vitamin D obtained from the diet or synthesised in the skin is biologically inactive. It becomes active by two enzymatic hydroxylation steps, the first occurring in the liver and the second in the kidneys.[1][3] Since most mammals can synthesise sufficient vitamin D with adequate sunlight exposure, it is technically not essential in the diet and thus not a true vitamin. Instead it functions as a hormone; the activation of the vitamin D pro-hormone produces calcitriol, the active form. Calcitriol then exerts its effects via the vitamin D receptor, a nuclear receptor found in various tissues throughout the body.[6]

Vitamin D obtained from the diet or synthesised in the skin is biologically inactive. It becomes active by two enzymatic hydroxylation steps, the first occurring in the liver and the second in the kidneys.[1][3] Since most mammals can synthesise sufficient vitamin D with adequate sunlight exposure, it is technically not essential in the diet and thus not a true vitamin. Instead it functions as a hormone; the activation of the vitamin D pro-hormone produces calcitriol, the active form. Calcitriol then exerts its effects via the vitamin D receptor, a nuclear receptor found in various tissues throughout the body.[6]