Vitamin E is an antioxidant. It plays a role in your immune system and metabolic processes. Good sources of vitamin E include, Vegetable oils, Margarine, Nuts and seeds and Leafy greens. Vitamin E is also added to foods like cereals. Most people get enough vitamin E from the foods they eat. People with certain disorders, such as liver diseases, cystic fibrosis, and Crohn’s disease may need extra vitamin E.