The term vitamin E is used to describe eight lipophilic, naturally occurring compounds that include four tocopherols and four tocotrienolsdesignated as a‐, b‐, g‐, and d‐. The most well known function of vitamin E is that of a chain‐breaking antioxidant that prevents the cyclic propagation of lipid peroxidation. Despite its antioxidant function, dietary vitamin E requirements in humans are limited only to a‐tocopherol because the other forms of vitamin E are poorly recognized by the hepatic a‐tocopherol transfer protein (TTP), and they are not converted to a‐tocopherol by humans..