Also known as ascorbic acid, vitamin C is a water-soluble vitamin needed by the body for hundreds of vital metabolic reactions. Vitamin C is not produced in the human body, yet it is essential for the formation of collagen, connective tissue, and immune system factors. It also has anti-inflammatory and antioxidant functions. The only way to obtain Vitamin C is through a diet high in Vitamin C or by supplementation. Vitamin C is by far the most consumed dietary supplement. It acts as an antioxidant; prevents colds and boosts immunity; promotes wound healing; protects against effects of stress; cancer prevention
Because it is required in the formation of collagen and connective tissue, Vitamin C, literally holds the body together, building strong bones, teeth, blood vessels, cartilage, tendons and ligaments. It also enhances wound healing. Vitamin C is also important in the immune systems surveillance and defense against foreign invaders and tumor cells. Vitamin C is important in preventing cardiovascular disease by facilitating fat metabolism and protecting tissues from free radical damage with its powerful function as an antioxidant. Vitamin C is a water-soluble antioxidant functions within the aqueous but it can help restore the antioxidant potential of vitamin E (a fat-soluble antioxidant). It also assists the nervous system by converting certain amino acids into neurotransmitters.
Vitamin C prevents against infections probably by strengthening cell membranes, thereby preventing entrance of the virus to the interior of the cell, and also by supporting immune cell function. Studies in subjects under heavy acute physical stress show that vitamin C decreases common cold incidence by half. In other studies, healthy subjects consuming low levels of vitamin C (below 60 mg/day), have a cold incidence that is about one-third lower following vitamin C supplementation.
Classic Vitamin C deficiency creates scurvy, a condition characterized by gum disease, pain in the muscles and joints, skin lesions, fatigue and bleeding. An adult needs 10 milligrams of vitamin C per day to prevent scurvy. This is the absolute minimum; some studies have shown that a daily dose of 100 mg or more may be needed to maintain or maximize the body pool of vitamin C. However, dietary surveys carried out in the US population indicate that less than 12 percent of US children and adults meet the current RDA of 90 mg for men and 75 mg for women.
In it’s role as antioxidant Vitamin C is probably necessary in much higher amounts than the RDA. Vitamin C protects the DNA of the cells from the damage caused by free radicals and mutagens. It prevents harmful genetic alterations within cells and protects lymphocytes from mutations to the chromosomes. Vitamin C may be especially important with our current level of environmental pollution because it combats the effects of many such toxins, including ozone, carbon monoxide, hydrocarbons, pesticides and heavy metals, and nitrates contained in many foods.
Vitamin C prevents free radical damage in the lungs and may even help to protect the central nervous system from such damage. In a study of guinea pigs, an ascorbic acid pretreatment effectively diminished the acute lung damage caused by the introduction of superoxide anion free oxygen radicals to the trachea. Ascorbic acid also was tested as an antioxidant to inflammatory reaction in mice. High doses given after but not before the injury successfully suppressed edema
Vitamin C also works along with glutathione peroxidase (a major free radical-fighting enzyme) to revitalize vitamin E, a fat-soluble antioxidant. In addition to its work as a direct scavenger of free radicals in fluids, then, vitamin C also contributes to the antioxidant activity in the lipids. In human and animal studies, Vitamin C and Vitamin E working together reduce lipids in subjects with diabetes, cerebral arteriosclerosis or a heart disorder. Together, they can help to prevent the blood from clotting, a condition that contributes to the risk of stroke. This combination may offer protection against cataracts as well.
The synergistic combination of vitamins C and E may be further enhanced by the addition of vitamin A. In one study of 30 elderly long-stay patients, for example, this trio was effective in improving certain aspects of cell-mediated immunity, such as the number of T cells, T4 subsets and the ratio of T4 to T8 cells. In another study, a complex of vitamins A, E and C significantly enhanced the "characteristics of enzymatic and non-enzymatic antioxidant protection of the liver" in mice. A classic antioxidant combination - vitamins C and E, beta carotene and selenium - helped to alleviate pancreatitis, or an inflammation of the pancreas, in a study of 28 patients. (See Citation List below)
Dietary Sources: A citrus fruits (oranges, grapefruit, lemons), strawberries, tomatoes, broccoli, brussel sprouts, peppers and cantaloupe. Vitamin C is a fairly “fragile” vitamin and can be easily destroyed by cooking or exposure of food to oxygen.
Dosage: Although the RDA for vitamin C has recently been raised from 60mg to 75-90mg (higher for men), it is well established that almost everybody can benefit from higher levels. For example, the vitamin C recommendation for cigarette smokers is 100-200mg per day because smoking destroys vitamin C in the body.
Side Effects: As a water-soluble vitamin, ascorbic acid C is extremely safe even at relatively high doses (because most of the excess is excreted in the urine). At high doses (over 1000mg/day), some people can experience gastrointestinal side effects such as stomach cramps, nausea, and diarrhea.
In our literature review of Vitamin C, we found studies in Human, Animal and Basic research that focus on:
1. Antioxidant potential in treating the oxidative stress of heart disease.
2. Antitumor potential
3. Deficiency in brain grey matter in the elderly
4. Protection against high levels of insulin
5. Improvement of mental performance in the elderly
6. Adjunctive treatment in cancer chemotherapy to prevent oxidative stress
7. Use in diabetes mellitus to protect blood vessels
8. Protective effects against cancer
9. Reducing cholesterol and the apo-B lipid fraction, LDL cholesterol, triglycerides, and increasing beneficial HDL cholesterol.
10. Reducing arsenic-induced oxidative stress.
11. Use in chronic glomerulonephritis to reduce oxidative tissue damage
12. Prevents downregulation of endothelial NOS expression in hypercholesterolemia in vivo and in vitro.
13. Prevention of cataracts.
14. Prevention of Alzheimer's.
Vitamin C Abstract Summaries (460)