CoQ10 and vitamin E are both lipid-soluble nutrients with redox potential. Tocopherol and/or tocotrienol protect CoQ10 from oxidative damage and reduce ubiquinone in situ. Specifically, vitamin E protects the oxidation of ubiquinol to ubiquinone ex vivo and reduces ubiquinone to ubiquinol in situ. Vitamin Es with higher ratio of tocotrienol-to-tocopherol cause a higher ratio of ubiquinol-to-ubiquinone. Additionally tocopherol and/or tocotrienol protect vitamin A oxidation from retinol to retinoic acid.