Vitamin D synthesis pathway

The **Vitamin D synthesis pathway** refers collectively to a series of biochemical reactions that convert precursors into active forms of vitamin D. In humans, this begins with UVB-induced conversion of 7-dehydrocholesterol in skin into cholecalciferol (vitamin D3), followed by hepatic hydroxylation by vitamin D 25-hydroxylase (*CYP2R1*) producing 25-hydroxyvitamin D3. This is further hydroxylated in the kidney by 1α-hydroxylase (*CYP27B1*) to form calcitriol [1α,25-dihydroxyvitamin D], which is biologically active[4][5][6]. The active form then binds and activates nuclear vitamin D receptor (*VDR*), regulating gene expression involved in calcium and phosphate homeostasis[4][5]. The term "Vitamin D synthesis pathway" does not refer to a single molecular target but encompasses multiple enzymes and regulatory proteins; therefore it is not considered a therapeutic target itself but rather describes an essential physiological process[4][5][6]. Notes on correctness: There is something incorrect about using "Vitamin D synthesis pathway" as a drug target. It describes an entire metabolic sequence involving several distinct molecular targets—such as *CYP2R1*, *CYP27B1*, and *VDR*—rather than one discrete molecule or receptor suitable for direct pharmacological targeting[4][5][6]. For structured data purposes focused on drug discovery or pharmacology, it would be more appropriate to specify one enzyme or receptor within this cascade. If you need information about any specific enzyme/receptor from this pathway—such as "Vitamin D receptor," "Vitamin D 25-hydroxylase," etc.—please specify so detailed structured data can be provided for that entity.

Other names

Vitamin D biosynthesis pathwayVitamin D metabolic pathwaySteroid hormone biosynthesis (Vitamin D branch)