Crystal structure of the human vitamin D receptor ligand binding domain complexed with 1-((((1S,2R,6R,Z)-2,6-dihydroxy-4-((E)-2-((1R,3aS,7aR)-1-((R)-6-hydroxy-6-methylheptan-2-yl)-7a-methylhexahydro-1H-inden-4(2H)-ylidene)ethylidene)-3-methylenecyclohexyl)oxy)methyl)cyclopropanecarbonitrile