Vitamin C functions, uses, and health benefits

The antioxidant properties of vitamin C - Vitamin C is one of many antioxidants. Antioxidants are nutrients that block some of the damage caused by free radicals, which are by-products that result when our bodies transform food into energy. Vitamin C neutralizes potentially harmful reactions in the watery parts of the body, such as the blood and the fluid inside and surrounding cells. Vitamin C may help decrease total and LDL cholesterol and triglycerides, as well as increase HDL levels. Vitamin C's antioxidant activity may be helpful in the prevention of some cancers and cardiovascular disease. The antioxidant properties of vitamin C are thought to protect smokers, as well as people exposed to secondhand smoke, from the harmful effects of free radicals. Vitamin C strengthens the collagen structure of arteries, lowers total cholesterol, and blood pressure, an inhibits platelet aggregation.

Vitamin C and heart disease - Vitamin C may protect against heart disease by reducing the stiffness of arteries and the tendency of platelets to clump together. Long-term administration of vitamin C reverses endothelial vasomotor dysfunction in patients with coronary artery disease. Under most circumstances, dietary vitamin C is adequate for protecting against the development of or consequences from cardiovascular disease. When taken with vitamin E, vitamin C helps protect LDL ("bad") cholesterol from oxidation, thus preventing plaque buildup in coronary arteries. Individuals with high blood levels of vitamin C have significantly reduced risk of stroke. The risk of stroke was inversely related to vitamin C in the bloodstream. Vitamin C improves nitric oxide activity. Nitric oxide is needed for the dilation of blood vessels, potentially important in lowering blood pressure and preventing spasms of arteries in the heart that might otherwise lead to heart attacks. Vitamin C has reversed dysfunction of cells lining blood vessels. The normalization of the functioning of these cells may be linked to prevention of heart disease.

Vitamin C and cancer - Vitamin C may have cancer-preventive activity, at least for certain types of cancer. As a powerful antioxidant, vitamin C may help to fight cancer by protecting healthy cells from free-radical damage and inhibiting the proliferation of cancerous cells. Vitamin C to improve the antineoplastic activity of doxorubicin, cisplatin and paclitaxel. The mechanism of the effect may be pro-oxidant, not antioxidant, activity of the vitamin in potentiating the effects of these chemotherapeutic agents. High concentratins of ascorbic acid in gastric juice may reduce the risk of gastric cancer by inhibiting the formation of carcinogenic N-nitroso compounds. Ascorbic acid is toxic to viruses and bacteria and other such harmful cells. It is also toxic to cancerous cells and a little less toxic to non-cancerous cells and so it is used therapeutically in cancer therapy. Many of the pollutants which now pervade our environment can cause carcinogenic, toxic or mutagenic effects. Vitamin C may be able to combat these harmful effects, in part by stimulating detoxifying enzymes in the liver.

Vitamin C and cllagen, connective tissue - As a participant in hydroxylation, vitamin C is needed for the production of collagen in the connective tissue. These fibres are ubiquitous throughout the body; providing firm but flexible structure. Vitamin C is involved in the hydroxylation of proline to from hydroxyproline in the synthesis of collagen, a protein substance on which the integrity of cellular structure in all fibrous tissues depends. Collagen is the "glue" that strengthens many parts of the body, such as muscles and blood vessels. Collagen is a protein needed to develop and maintain healthy teeth, bones, gums, cartilage, vertebrae discs, joint linings, skin and blood vessels. Vitamin C is essential for the healing of wounds, and for the repair and maintenance of cartilage, bones, and teeth.

Vitamin C and immune system - Vitamin C may be useful as an immune stimulator and modulator in some circumstances. Vitamin C promotes resistance to infection through the immunologic activity of leukocytes, the production of interferon, and the process of inflammatory reaction, or the integrity of the mucous membranes. Vitamin C stimulates the immune system. Through this function, along with its antioxidant function, it may help in the prevention and treatment of infections and other diseases. There is some evidence that vitamin C inhibits the replication of human immunodeficiency virus 1 (HIV-1).

Other functions of vitamin C - Vitamin C has been reported to reduce activity of the enzyme, aldose reductase, in people. Aldose reductase is the enzyme responsible for accumulation of sorbitol in eyes, nerves, and kidneys of people with diabetes. Vitamin C levels in the eye decrease with age and that supplementing with vitamin C prevents this decrease, possibly leading to a lower risk of developing cataracts. Vitamin C may be helpful in protecting against some of the lipid oxidation caused by smoking. Vitamin C may be helpful in chronic diseases characterized by oxidative damage to biological molecules. People with recurrent boils (furunculosis) may have defects in white blood cell function that are correctable with vitamin C supplementation.