Researchers at Toyohashi University of Technology, in cooperation with researchers at Teijin Pharma Ltd. and Teikyo University, have highlighted the possibility that chirality of vitamin D derivatives can affect the protonation states of histidine residues in the vitamin D receptor protein via ab initio molecular simulations and biomedical analyses. This finding emphasizes that protonation states should be considered more precisely in molecular simulations, when investigating specific interactions between candidate drugs and target proteins related to disease pathogenesis.