E-400 with Mixed Tocopherols contains 400 IU of vitamin E as d-alpha tocopherol – the natural form of vitamin E. In addition, it contains 67 mg of mixed tocopherols. Mixed tocopherols are a combination of the four tocopherols present in vitamin E: delta, alpha, gamma and beta tocopherol. Some mixed tocopherol supplements may not contain all four tocopherols but instead might combine two or three in various concentrations. In rare cases, a manufacturer may market a synthetic form of alpha tocopherol by itself as a mixed tocopherol.