Riboflavin photosensitized singlet oxygen oxidation of vitamin D

Ascorbic acid is less effective than alpha-tocopherol in quenching singlet oxygen during the oxidation of vitamin D2 in the presence of 15 ppm riboflavin. This could be attributable to the fact that the stability of ascorbic acid is determined by the pH. This research aimed to prove the hypothesis that riboflavin-photosensitized singlet oxygen oxidation of vitamin D takes place. It also sought to establish the kinetics and mechanisms for quenching singlet oxygen oxidation of vitamin D. Oxidation of vitamin D was not seen in samples without riboflavin stored in the light or in samples with riboflavin stored in the dark.