This gene encodes vitamin D3 receptor which is a member of the nuclear hormone receptor superfamily of ligand-inducible transcription factors This receptor also functions as a receptor for the secondary bile acid lithocholic acid Downstream targets of vitamin D3 receptor are principally involved in mineral metabolism though this receptor regulates a variety of other metabolic pathways such as those involved in immune response and cancer Mutations in this gene are associated with type II vitamin D-resistant rickets A single nucleotide polymorphism in the initiation codon results in an alternate translation start site three codons downstream Alternatively spliced transcript variants encoding different isoforms have been described for this gene A recent study provided evidence for translational readthrough in this gene and expression of an additional C-terminally extended isoform via the use of an alternative in-frame translation termination codon