Vitamin C, also called L- ascorbic acid, is a water-soluble vitamin, which is rich in fruits and vegetables. It plays a regulatory role in redox metabolic reaction, and the lack of it will cause scurvy. Under normal circumstances, most of vitamin C is decomposed into oxalic acid or combined with sulfuric acid to generate ascorbic acid -2- sulfuric acid, and the other part can be directly excreted from urine.

The chemical name of vitamin A is retinol, which is the earliest discovered vitamin. There are two kinds of vitamin A, one is vitamin A alcohol, which is the original form of vitamin A (only exists in animal food); The other is carotene, which is converted into a preformed substance of vitamin A in the body; The measurement units of vitamin A are USP unit, IU unit and re unit.

Vitamin E is a fat-soluble vitamin, and its hydrolysate is tocopherol, which is one of the most important antioxidants. Soluble in fat, ethanol and other organic solvents, insoluble in water, stable to heat and acid, unstable to alkali, sensitive to oxygen and insensitive to heat, but the activity of vitamin E decreased obviously during frying. Tocopherol can promote the secretion of sex hormones and increase the vitality and quantity of male sperm; Can increase female estrogen concentration, improve fertility, prevent miscarriage, and can also be used for preventing and treating male infertility, burn, frostbite, capillary hemorrhage, climacteric syndrome, and caring skin.

Recently, it has also been found that vitamin E can inhibit the lipid peroxidation reaction of eye lens, dilate peripheral blood vessels, improve blood circulation and prevent the occurrence and development of myopia. The phenolic hydroxyl group on the benzene ring of vitamin E is acetylated, and the ester is hydrolyzed into phenolic hydroxyl group to form tocopherol. People often mistake vitamin E for tocopherol.