This mitochondrial protein initiates the degradation of 1,25-dihydroxyvitamin D3, the physiologically active form of vitamin D3, by hydroxylation of the side chain to form calcitroic acid.
In regulating the level of vitamin D3, this enzyme plays a role in calcium homeostasis and the vitamin D endocrine system.Has a role in maintaining calcium homeostasis. Catalyzes the NADPH-dependent 24-hydroxylation of calcidiol
(25-hydroxyvitamin D(3)) and calcitriol (1-alpha,25-dihydroxyvitamin D(3)). CYP24A1 can perform up to 6 rounds of
hydroxylation of calcitriol leading to calcitroic acid. It also shows 23-hydroxylating activity leading to
1-alpha,25-dihydroxyvitamin D(3)-26,23-lactone as end product.