Highly reactive oxygen metabolites are generated in all cells (the most important include (a) superoxide anion, (b) hydroxyl radicals, and (c) hydrogen peroxide), and are scavenged by protective systems, the adequacy of which depends on the sufficiencyh of the nutrient supply; the main systems are: (a) antioxidants such as vitamin E, (b) glutathione* peroxidase; (c) superoxide dimutase; (d) catalas.
