Tocopherol is a general term that describes Vitamin E. There are 8 known Vitamin E isomers, these include alpha, beta, delta and gamma tocopherols and tocotrienols. When the letter "d" appears before alpha-Tocopherol, it means that the vitamin E is all natural. If there is a "dl" before alpha-Tocopherol, it is a synthetic vitamin E, which is less expensive to create and some believe that it is not as bioavailable as the natural form. Natural Vitamin E may be more bioavailable than synthetic (dl), tocopherols.