Cholecalciferol is only found in individuals that have used or taken this drug. It is a derivative of 7-dehydroxycholesterol formed by ultraviolet rays breaking of the C9-C10 bond. It differs from ergocalciferol in having a single bond between C22 and C23 and lacking a methyl group at C24. [PubChem]The first step involved in the activation of vitamin D3 is a 25-hydroxylation which is catalysed by the 25-hydroxylase in the liver and then by other enzymes. The mitochondrial sterol 27-hydroxylase catalyses the first reaction in the oxidation of the side chain of sterol intermediates. The active form of vitamin D3 (calcitriol) binds to intracellular receptors that then function as transcription factors to modulate gene expression. Like the receptors for other steroid hormones and thyroid hormones, the vitamin D receptor has hormone-binding and DNA-binding domains. The vitamin D receptor forms a complex with another intracellular receptor, the retinoid-X receptor, and that heterodimer is wh
Solubility Insoluble (NTP, 1992)
Mol. Weight
384.60
State
Vitamin d3 appears as fine colorless crystals. Water insoluble. (NTP, 1992)
See origin →
Functions
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Antioxidant
Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.