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 Vitamin C is a water-soluable vitamin with various biological functions and includes L-ascorbic acid, commonly called ascorbic acid, and L-dehydroascorbic acid, substances with antiscorbutic activity. Ascorbic acid is the form of vitamin C found primarily in our diets. The names ascorbate, vitamin C and ascorbic acid are used interchangeably.
Vitamin C is an important antioxidant that helps provide LDL cholesterol with protection from oxidative damage. LDL leads to heart disease only after it has been damaged. Vitamin C might also protect from heart disease as it reduces the clumping of platelets and the stiffness of arteries.
Vitamin C also helps strengthen body parts, such as blood vessels and muscles, by helping to make collagen. It also is a natural antihistamine, helps heal wounds, fights viruses, assists in liver bile formation, and detoxifies the body of substances such as alcohol.
Nitric oxide activity is also improved by vitamin C. Nitric oxide helps to dilate blood vessels and may help prevent artery spasms and lower blood pressure that could potentially lead to heart attacks. Vitamin C has been shown to reverse the dysfunction of cells lining the blood vessels. By helping to normalize these cells, heart disease may be prevented.
As people age, levels of vitamin C present in the eye begin to decrease. Supplementation may help lower the risk of developing cataracts by preventing this decrease.
The activity of the enzyme aldose reductase is reduced by vitamin C. This enzyme causes sorbitol to accumulate in the nerves, kidneys, and eyes of those suffering from diabetes. This accumulation is thought to cause the deterioration of those body parts. By reducing the enzyme’s activity, vitamin C helps provide protection to those with diabetes.
The retaining and accumulation of lead may be stopped by vitamin C. An early study showed that those with high levels of vitamin C in their blood have lower chances of having high levels of lead in their blood.
Furunculosis, or recurrent boils, may be caused by white blood cells with defects that can be corrected by vitamin C. One study showed that taking 1 gram of vitamin C each day, for a period of four to six weeks, normalized the defects in white blood cells.
Vitamin C has been used to help people with these health conditions:
- Anemia (when deficient)
- Athletic performance (when deficient)
- Bronchitis
- Bruising
- Burns (in combination with vitamin E for prevention of sunburn)
- Capillary fragility
- Common cold
- Gingivitis (when deficient)
- Glaucoma
- Heart attack
- High cholesterol (offers protection for LDL cholesterol)
- Infection
- Infertility (male)
- Reflex sympathetic dystrophy (prevention)
- Scurvy
- Wound healing
Suggested Dosage and Administration
Plasma and lymphocyte levels are almost maximized when 200 milligrams are taken daily. Doses can range from 500 milligrams to 2 grams daily. Doses are sometimes increased in 4 to 5 grams daily when people are trying to fight off a cold. This is done to cause an antihistaminic action from the vitamin C. Doses of 5 grams daily for a period of 4 weeks may inhibit Helicobacter pylori. High doses of vitamin C may provide extra detoxification from carcinogens found in the stomach.
Supporting Literature
Wilkinson IB, Megson IL, MacCallum H, et al. Oral vitamin C reduces arterial stiffness and platelet aggregation in humans. J Cardiovasc Pharmacol 1999;34:690–692.
Valkonen MM, Kuusi T. Vitamin C prevents the acute atherogenic effects of passive smoking. Free Radic Biol Med 2000 Feb 1;28:428–435.
Hoffer A. Ascorbic acid and kidney stones. Can Med Assoc J 1985;32:320.
Balz F. Antioxidant Vitamins and Heart Disease. Presented at the 60th Annual Biology Colloquium, Oregon State University, February 25, 1999.
Levine M, Rumsey SC, Daruwala R, et al. Criteria and recommendations for vitamin C intake. JAMA 1999;281:1415–1423.
Levine M, Conry-Cantilena C, Wang Y, et al. Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. Proc Natl Acad Sci 1996;93:3704–709.
Jacques PF, Chylack LT Jr. Epidemiologic evidence of a role for the antioxidant vitamins and carotenoids in cataract prevention. Am J Clin Nutr 1991;53:352S–5S.
Jacques PF, Chylack LT, McGandy RB, Hartz SC. Antioxidant status in persons with and without senile cataract. Arch Ophthalmol 1988;106:337–340.
Seddon JM, Christen WG, Manson JE, et al. The use of vitamin supplements and the risk of cataract among US male physicians. Am J Public Health 1994;84:788–792.
Balz F. Antioxidant vitamins and heart disease. Presented at the 60th Annual Biology Colloquium, Oregon State University, Corvallis, Oregon, February 25, 1999.
Kharb S. Total free radical trapping antioxidant potential in pre-eclampsia. Int J Gynaecol Obstet 2000;69:23–26.
Makoff R. Vitamin replacement therapy in renal failure patients. Miner Electrolyte Metab 1999;25:349–351.
Johnston CS. Biomarkers for establishing a tolerable upper intake level for vitamin C. Nutr Rev 1999;57:71–74.
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