PathwayStep1656 PathwayStep1649 Further hydroxylation of calcidiol in kidney to form calcitriol 25-Hydroxylation of vitamin D3 in liver PathwayStep2665 PathwayStep2666 PathwayStep2667 PathwayStep2668 Vitamins A number of CYPs can act upon vitamins. Authored: Jassal, B, 2008-05-19 12:57:01 Edited: Jassal, B, 2008-05-19 12:57:01 GENE ONTOLOGYGO:0006766 Pubmed15102545 Pubmed16584116 Reactome Database ID Release 43211916 Reactome, http://www.reactome.org ReactomeREACT_13450 Reviewed: D'Eustachio, P, 2008-05-28 08:30:54 CYP24A1 catalyzes the initial step in the deactivation of the hormonally active form of vitamin D3 CYP26A1 breaks down all-trans-retinoic acid by 4-hydroxylation CYP26B1 also deactivates all-trans-retinoic acid by 4-hydroxylation CYP26C1 deactivates 9-cis-retinoic acid by 4-hydroxylation