(1S)-Calcitriol (1α,25-Dihydroxy-3-epi-vitamin-D3) is a natural metabolite of 1α,25-dihydroxyvitamin D 3 (1α,25(OH) 2 D 3 ). (1S)-Calcitriol exhibits potent vitamin D receptor (VDR)-mediated actions such as inhibition of keratinocyte growth or suppression of parathyroid hormone secretion. In Vitro 3‐epi‐Calcitroic acid is an end product of (1S)-Calcitriol (1α,25-Dihydroxy-3-epi-vitamin-D3; 3‐epi‐1a,25(OH) 2 D 3 ) metabolism by rat CYP24A1. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid