VDR and hypercalcemia disease: This study shows that both 1,25(OH)2D3 and 20-epi-1,25(OH)2D3[11] induce VDR binding to CYP24A1 and TRPV6 loci in the intestine, but the analog elicits a prolonged VDR binding to these genes leading to its superagonistic characteristics such as hypercalcemia in vivo (Zella et al., 2009).