Vitamin C is one of the most needed nutrients for human body. It has many physiological functions, such as anti-oxidation, enhancing human immunity and improving the utilization rate of iron, calcium and folic acid. For infants, the elderly and people with low vegetable intake, fruit is the main source of vitamin C.
Many common fruits, such as bananas, apples, pears, peaches and watermelons, have low vitamin C content (< 10 mg/100 g).
Citrus, grapes, mangoes, pineapples, cantaloupes and other fruits have higher vitamin C content (10 ~ 30mg/ 100g).
Such as fresh jujube, kiwi fruit, strawberry, papaya, litchi and so on. The content of vitamin C is very high (> 40 mg/100 g). Among them, the vitamin C content of fresh jujube is far ahead, which is 243 mg/100 g.
Extended data:
Health care function of vitamin c
1. synthesis of collagen: the human body is composed of cells, which are connected by intercellular substance, and the key component of intercellular substance is collagen. Collagen accounts for 1/3 of the protein of the body, which generates connective tissue and constitutes the bones of the body. Such as bones, blood vessels and ligaments. , determine the elasticity of the skin, protect the brain, and contribute to the healing of human wounds.
2. Anti-scurvy: The strength of blood vessel wall has a great relationship with VC. Microvessel is the smallest of all blood vessels, and its wall may be only one cell thick, and its strength and elasticity are determined by collagen.
When VC is insufficient in the body, microvessels are easy to rupture. Therefore, when vitamin C is deficient, congestion and cyanosis will appear on the skin surface; When it happens in the body, it can cause pain and joint swelling. In severe cases, bleeding of stomach, intestine, nose, kidney and periosteum may occur.
3, gingival atrophy, bleeding. A healthy chewing gum tightly wraps every tooth. Gingiva is soft tissue, which is prone to atrophy and bleeding when lacking protein, calcium and VC.
4. Prevent arteriosclerosis. It can promote the excretion of cholesterol and prevent cholesterol from depositing on the inner wall of arteries.
5. It is a water-soluble antioxidant. It can reduce and protect other antioxidants, such as vitamin A, vitamin E, unsaturated fatty acids, etc., and prevent the harm of free radicals to human body.
6. Treat anemia. It can reduce trivalent iron which is difficult to be absorbed and utilized into ferrous iron, promote the absorption of iron by meridians, improve the utilization rate of iron by liver, and help to treat iron deficiency anemia.
7. Cell damage prevents cell variation; Prevent nitrite and secondary amine from forming strong carcinogen nitrosamine. Someone once dissected a patient who died of cancer and found that the VC content in the patient was almost zero.
8. Protect cells, detoxify and protect liver. In human life activities, it is very important to ensure the integrity and normal metabolism of cells. Therefore, glutathione and enzymes play an important role. Glutathione is a short peptide composed of glutamic acid, cystine and glycine, which has redox effect in the body. It exists in two forms, namely oxidation type and reduction type, and reduction type plays an important role in ensuring the integrity of cell membrane.
VC is a strong antioxidant, which reduces oxidized glutathione to reduced glutathione through its own oxidation, thus playing an antioxidant role. Enzymes are catalysts for biochemical reactions, and some enzymes need free sulfhydryl (-SH) to keep their activity. VC can reduce disulfide bond (-S-S) to -SH, thus improving the activity of related enzymes and playing an antioxidant role.
To sum up, as long as VC is sufficient, VC, glutathione and -SH will form a powerful antioxidant combination, scavenge free radicals, prevent lipid peroxidation and toxic effects of some chemicals, and protect the detoxification ability of the liver and the normal metabolism of cells.
9. Improve human immunity. White blood cells are rich in VC, and when the body is infected, the VC in white blood cells decreases sharply. VC can enhance the chemotaxis and deformability of neutrophils and improve their bactericidal ability. Promote the generation of lymphocytes and improve the body's ability to identify and kill foreign cells and malignant cells. Participate in the synthesis of immunoglobulin. Improve the activity of complement esterase in CI and increase the production of complement CI. Promote the production of interferon, interfere with the transcription of virus mRNA, and inhibit the proliferation of virus.
10, improve the body's stress ability. Abnormal stimuli to the human body, such as severe pain, cold, lack of oxygen, strong mental stimulation, etc., will trigger a state of tension against abnormal stimuli. This state is accompanied by a series of organisms, including sympathetic nerve excitement, adrenal medulla and increased secretion of corticosteroids.
Adrenaline and norepinephrine secreted by adrenal medulla are converted from tyrosine, which requires VC. Vitamin C entering the human body is rapidly distributed in 20 tissues and organs. Under normal circumstances, the human vitamin C bank is 1500 mg. Most of the excess is excreted with urine, and a small part is excreted with stool, sweat and respiratory tract.
In the case of infection, the human body needs 20-40 times as much as usual, and all drugs will destroy VC in the body, so it is very beneficial to supplement VC when the human body is in a state.
Dr. Pauling, an American scientist who won the Nobel Prize twice and died at the age of 93, published the book Vitamin C and the Common Cold in 1970 based on his years of research. The viewpoint in the book is that taking more than 1000 mg of natural vitamin C every day can prevent colds; Vitamin c can resist viruses. This book was rated as the best popular science reading in the United States that year.
In short, the role of vitamin C in improving resistance, preventing cardiovascular diseases, participating in hematopoiesis and effectively resisting free radicals has been clearly certified.
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