Vitamin C has strong reducibility and is easily oxidized to dehydrovitamin C, but its reaction is reversible. Ascorbic acid and dehydroascorbic acid have the same physiological function. However, if dehydroascorbic acid continues to oxidize to diketones, the reaction will be irreversible and lose its physiological function completely.
Vitamin C is necessary for the formation of antibodies and collagen, tissue repair (including some redox effects), metabolism of phenylalanine, tyrosine and folic acid, utilization of iron and carbohydrates, synthesis of fat and protein, maintenance of immune function, hydroxylation of serotonin, maintenance of vascular integrity and promotion of non-heme iron absorption.
At the same time, vitamin C also has the functions of antioxidation, anti-free radical and inhibition of tyrosinase formation, thus achieving the effect of whitening and lightening spots.
Extended data:
Symptoms of insufficient VC intake:
1, general symptoms
The onset is slow, and vitamin C deficiency takes about 3 ~ 4 months before symptoms appear. There are no specific symptoms in the early stage, and patients often appear pale, fatigue, loss of appetite, depression and other manifestations. Children are irritable, do not gain weight, and may be accompanied by low fever, vomiting and diarrhea.
2, bleeding symptoms
Skin petechiae is its outstanding performance. When the patient's skin is slightly squeezed, scattered bleeding spots may appear, and purpura and ecchymosis are easy to appear after the skin is hit or squeezed. With the progress of the disease, the patient may have keratinization and bleeding around the hair follicle, and the hair roots are curly and fragile. Gums often swell and bleed, which is easy to cause secondary infection, and teeth may loose and fall off due to alveolar necrosis.
There may also be nosebleeds and orbital subperiosteal bleeding causing exophthalmos. Occasionally, gastrointestinal bleeding, hematuria, intra-articular bleeding and even intracranial bleeding can be seen. Patients may have sudden convulsions, shock and even death.
3. Anemia
Because of long-term bleeding, and vitamin C deficiency can affect the absorption of iron, late patients are often accompanied by anemia and pallor. Anemia is often moderate, usually cellular anemia with normal hemoglobin. In a series of cases, 1/5 patients may be megaloblastic anemia.
4. Skeletal symptoms
Subperiosteal hemorrhage or metaphyseal dislocation of long bones can cause pain in the affected limb, leading to pseudoparalysis. One of the early symptoms of the baby is that the limbs are frog-shaped, and any movement of the limbs will make it cry, mainly because the joint capsule is full of bloody exudate, so the limbs can only be flexed but not straightened.
Baidu encyclopedia -VC