Editorial: Vitamin D 1α-Hydroxylase Knockout Mice as a Hereditary Rickets Animal Model

The editorial discussed the role of vitamin D 1α-hydroxylase (CYP27B1) in mineral homeostasis and bone formation, highlighting its importance in converting vitamin D3 into its active form, 1α,25(OH)2D3. The study by Dardenne et al. introduced knockout mice lacking 1α(OH)ase, which developed rickets and osteomalacia, similar to vitamin D-dependent rickets type I (VDDRI) patients. These mice showed decreased serum calcium and 1α,25(OH)2D3 levels, confirming the enzyme's critical role in vitamin D metabolism. Unlike VDR knockout mice, 1α(OH)ase knockout mice did not develop alopecia, emphasizing the distinct roles of VDR and 1α(OH)ase in hair follicle development. The study suggested potential species differences in vitamin D metabolism and raised questions about the enzyme's roles in extra-renal tissues and tumors.