The structure of vitamin D2 (Ergocalciferol, CAS: 50-14-6) and D3 (Cholecalciferol, CAS: 67-97-0) were obtained from the PubChem database with CIDs 5280793 and 5280795, respectively. Ligands were energy minimized using MMFF94 force field in Open Babel , and the addition of hydrogen atoms at (at a pH of 7.4) with Gasteiger atomic charges were added using AutoDock tools . Finally, structures were converted to pdbqt format, as required by AutoDock Vina v1.1.2 for docking simulations.