Vitamin E refers primarily to alpha-tocopherol, a fat-soluble antioxidant essential for human health. It protects cell membranes from oxidative damage by scavenging free radicals and is commonly found in vegetable oils, nuts, and seeds. Chemically, it consists of a chromanol ring with a hydrophobic phytyl side chain, enabling its solubility in lipids. It plays a critical role in immune function, gene expression, and preventing lipid peroxidation. Deficiency can lead to neurological issues and hemolytic anemia. As a supplement, it is used in food preservation and cosmetics for its stabilizing properties. The compound exists in multiple stereoisomers, with the natural RRR form being most bioactive.