This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC’s registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726. Vitamin E was the fifth vitamin (fat-soluble) discovered in 1922 when researchers Herbert McLean Evans and Katherine S. Bishop found a dietary deficiency in laboratory rats produced infertility. Upon feeding the animals wheat germ, the rats were able to become pregnant. An alcohol substance was isolated from wheat germ and the formula C29H50O2 was determined. The name “tocopherol” was derived from the Greek words tos (childbirth) and phero (to bring forth), and the chemical designation for an alcohol (ol). Further research continued, and in 1936, Evans isolated alpha-tocopherol. Vitamin E was initially proposed as an antioxidant in 1945. In 1968, vitamin E was proposed to be used as an antioxidant to protect cell lipids from free radicals. The research data was used to set the initial 1968 recommended dietary allowance (RDA) for vitamin E at 30 IU. Vitamin E is a lipid-soluble phenolic cellular antioxidant compound obtained from plant sourc...