Calcitriol Receptor

The calcitriol receptor, more commonly known as the vitamin D receptor (VDR) and also known as NR1I1 (nuclear receptor subfamily 1, group I, member 1), is a member of the nuclear receptor family of transcription factors. Calcitriol, the active form of vitamin D, binds to the VDR, which then forms a heterodimer with the retinoid-X receptor. This then binds to hormone response elements on DNA resulting in expression or transrepression of specific geneproducts. The VDR not only regulates transcriptional responses but also involved in microRNA-directed post transcriptional mechanisms. In humans, the vitamin D receptor is encoded by the VDR gene. Glucocorticoids are known to decrease expression of VDR, which is expressed in most tissues of the body and regulate intestinal transport of calcium, iron and other minerals.