RESUMEN
In recent decades, the majority of ligands developed for the vitamin D receptor (VDR) bind at its deeply buried genomic ligand binding pocket. Theses ligands can be categorized into agonists and partial agonists/antagonists. A limited number of ligands, most of them peptides, bind the VDRâcoactivator binding site that is formed in the presence of an agonist and inhibit coactivator recruitment, and therefore transcription. Another solvent exposed VDRâligand binding pocket was identified for lithocholic acid, improving the overall stability of the VDR complex. Additional proposed interactions with VDR are discussed herein that include the alternative VDRâligand binding pocket that may mediate both non-genomic cellular responses and binding function 3 that was identified for the androgen receptor. Many VDR ligands increase blood calcium levels at therapeutic concentrations in vivo, thus the identification of alternative VDRâligand binding pockets might be crucial to develop non-calcemic and potent ligands for VDR to treat cancer and inflammatory disease.