Hydrogen Atom Transfer (HAT), Single Electron Transfer–Proton Transfer (SET–PT) and Sequential Proton-Loss Electron-Transfer (SPLET) were investigated. B3LYP, M05-2X and M06-2X functionals were employed in this study. Two solvation models were used for the solution-phase calculations in benzene and water: integral equation formalism polarized continuum model, IEF–PCM, as well as newer SMD method. All computational approaches provide identical trends. Comparison of found results with data obtained previously for phenol, α-tocopherol and flavonols indicates that vitamin B6 may show weaker antioxidant effect than naturally occurring phenolic antioxidants.