EC - Vitamin D 25-hydroxylase

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IntEnz Enzyme Nomenclature


Accepted name:
vitamin D 25-hydroxylase
Other names:
vitamin D2 25-hydroxylase
vitamin D3 25-hydroxylase
Systematic name:
calciol,NADPH—hemoprotein reductase:oxygen oxidoreductase (25-hydroxylating)



A microsomal enzyme isolated from human and mouse liver that bioactivates vitamin D3. While multiple isoforms (CYP27A1, CYP2J2/3, CYP3A4, CYP2D25 and CYP2C11) are able to catalyse the reaction in vitro, only CYP2R1 is thought to catalyse the reaction in humans in vivo [4]. The direct electron donor to the enzyme is EC, NADPH—hemoprotein reductase.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB


  1. Cheng, J. B., Motola, D. L., Mangelsdorf, D. J., Russell, D. W.
    De-orphanization of cytochrome P450 2R1: a microsomal vitamin D 25-hydroxilase.
    J. Biol. Chem. 278 : 38084-38093 (2003). [PMID: 12867411]
  2. Shinkyo, R., Sakaki, T., Kamakura, M., Ohta, M., Inouye, K.
    Metabolism of vitamin D by human microsomal CYP2R1.
    Biochem. Biophys. Res. Commun. 324 : 451-457 (2004). [PMID: 15465040]
  3. Strushkevich, N., Usanov, S. A., Plotnikov, A. N., Jones, G., Park, H. W.
    Structural analysis of CYP2R1 in complex with vitamin D3.
    J. Mol. Biol. 380 : 95-106 (2008). [PMID: 18511070]
  4. Zhu, J., Deluca, H. F.
    Vitamin D 25-hydroxylase - Four decades of searching, are we there yet?
    Arch. Biochem. Biophys. 523 : 30-36 (2012). [PMID: 22310641]

[EC created 2012 as EC, transferred 2016 to EC]