Abstract:Despite its historical name, vitamin D is not a vitamin at all but a hormone that, when activated, is a metabolically active steroid fat-soluble hormone that acts on cellular receptors. Vitamin D hormone is synthesized endogenously and then metabolized in the body, provi-ding that there are the necessary precursors and some factors — the effects of ultraviolet light on the skin. At the same time, vitamins themselves are nutrients, co-factors of biochemical reactions that are not synthesized in the body and can… Show more