In human body, vitamin C is a highly effective antioxidant, which is used to reduce the oxidative stress of ascorbic acid peroxidase substrate. There are many important biosynthetic processes that also require vitamin C.
Because most mammals can synthesize vitamin C through the liver, there is no problem of deficiency. However, a few animals, such as humans, primates and groundhogs, cannot synthesize themselves and must be ingested through food and drugs.
Participate in hydroxylation reaction. Hydroxylation is a necessary step in the synthesis or decomposition of many important substances in the body, and vitamin C must participate in the hydroxylation process.
(1) promotes collagen synthesis. When vitamin C is deficient, collagen synthesis is impaired, leading to scurvy.
⑵ Promote the synthesis of neurotransmitters (5- hydroxytryptamine and norepinephrine).
⑶ Promote steroid hydroxylation. Patients with high cholesterol should be supplemented with adequate vitamin C.
(4) Promote hydroxylation and detoxification of organic substances or poisons. Vitamin C can enhance the activity of mixed functional oxidase and enhance the detoxification (hydroxylation) process of drugs or poisons.
Restore. Vitamin C can be oxidized or reduced in vivo, so it can be used as a hydrogen donor and a hydrogen acceptor and plays an important role in the redox process in vivo.
(1) promotes antibody formation. High concentration of vitamin C helps to reduce cystine in food protein to cysteine, and then synthesize antibodies.
(2) Promote the absorption of iron. Vitamin C can reduce the hard-to-absorb trivalent iron to the easily-absorbed bivalent iron, thus promoting the absorption of iron. In addition, it can also make sulfhydryl groups such as ferrous complexing enzyme active, thus playing an effective role, so vitamin C is an important auxiliary drug for the treatment of anemia.
⑶ Promote the formation of tetrahydrofolate. Vitamin C can promote the reduction of folic acid to tetrahydrofolate, so it also has a certain effect on megaloblastic anemia.
⑷ Keep the activity of sulfhydryl enzyme.
Other functions
(1) Detoxification. Supplementing a large amount of vitamin C in the body can reduce the toxic effects of heavy metals such as lead, mercury, cadmium and arsenic on the body.
(2) prevent cancer. Many studies have proved that vitamin C can block the synthesis of carcinogenic N- nitroso compounds and prevent cancer.
⑶ Scavenging free radicals. Vitamin C can be converted into semi-deoxyascorbic acid and dehydroascorbic acid by gradually supplying electrons, and it can scavenge radical such as ultra-negative oxygen ion (O2-), hydroxyl radical (OH), organic radical (R) and organic peroxy radical (Roo). The tocopherol radical is reduced to tocopherol again, and the ascorbic acid radical generated by the reaction can be reduced to ascorbic acid by NADH2 system enzyme under certain conditions.