Molecular simulations were performed for vitamin D2 and D3 in the organic solvents' ethanol, butanone, and cyclohexane. The organic solvents were modeled using OPLS-AA with force fields generated using the LigPerGen tool. Water was modeled using TIP4P. In summary, we first equilibrated simulation boxes containing a single solute molecule (vitamin D2 or D3) in solution. The number of solvent molecules was chosen to obtain a cubic box with an edge length of approximately 4.6 nm. Initial structures were generated using Packmol , and then we subsequently performed 3,000 steps of steepest descent minimization to remove any bad contacts. We then performed a total of 14 ns of equilibration in the NPT ensemble. The minimization and all molecular dynamics calculations were performed using GROMACS version 2020.2 ().