NQO1 plays a role in ubiquinone and vitamin E quinone metabolism. The supplementation of Vitamin E is also recommended. There is no clinical evidence that use of vitamin E skincare products are effective. One trial showed low impact of pasture feeding on vitamin E and fatty acid composition. Treatment is oral vitamin E supplementation. They contain many types of lipids including plastoquinone, vitamin E, carotenoids and chlorophylls. Research on the effects of vitamin E on cardiovascular disease has produced conflicting results. Antioxidants such as vitamin C and vitamin E may inhibit lipid peroxidation. There were no significant benefits for vitamin E versus placebo. Sunflower oil is a rich source of vitamin E (tables). Further clinical studies show no benefit of vitamin E supplements for cardiovascular disease. Tentative evidence supports the use of vitamin E for prevention. Mustard greens are a moderate source of vitamin E and calcium. One review found thiamine and vitamin E to be likely effective. The effects of vitamin E supplementation on incidence of stroke were summarized in 2011.