Vitamin D-mediated regulation of CYP21A2 transcription - A novel mechanism for vitamin D action

► The transcriptional rate of CYP21A2 is downregulated by 1α,25-dihydroxyvitamin D3. ► The effect is mediated by nuclear receptor VDR and comodulators VDIR and WSTF. ► The expression level of comodulators may shift the suppression to stimulation. ► This paper reports a functional VDRE in the CYP21A2 promoter. ► Our data indicate a novel mechanism for vitamin D action.