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Vitamin C is one of the most discussed vitamins among the public and between scientists. A recent USA Today survey reported that 66% of Americans take a vitamin C supplement. Since the days when it was discovered as a cure for scurvy, a disease that plagued crewmen and travelers on long ocean voyages, its necessity has not been questioned. But the range and extent of its health benefits continue to be debated.
It plays a variety of roles in the body. Vitamin C works as an antioxidant to remove free radicals from cell fluids, which may be important in reducing risk of cancer, heart disease, cataracts, and dementia with aging. It also helps the body absorb iron from plant sources, helps produce collagen, a connective tissue that holds muscles, bones, and other tissues together. aids in wound healing, helps keep gums healthy, helps form and repair red blood cells, bones, and other tissues, and helps keep capillary walls and blood vessels firm, giving protection against bruising.
It is a commonly held belief by many people that Vitamin C prevents the common cold, but this has still not been proven. Controlled trials or studies found that high doses of vitamin C either did not prevent or reduce the frequency of colds, or that the effect was much less than previously reported. However, an adequate intake of vitamin C is important in fighting infection and extra vitamin C may have a mild antihistamine effect, which perhaps may reduce the symptoms of a cold or shorten its duration.
How much vitamin C do you need? This is a subject of debate among scientists. Currently the RDA is 60mg for adult nonsmokers and 100mg for smokers. As more is being learned about the role of vitamin C in chronic disease, some scientists recommend that the RDA for vitamin C should be raised to 100-120mg for all adults. An intake of about 100mg per day of vitamin C is needed to reach saturation in the blood. The proposed level can easily be obtained from food. By eating the recommended 5 to 9 servings of fruit and vegetables each day, one can quickly get well over 200mg of vitamin C. There is no evidence that getting an excess of vitamin C from food sources is harmful. In fact, foods, and particularly fruits and vegetables provide the ideal mixture of many nutrients which promote health and reduce risk of disease.
Even though vitamin C is a water-soluble vitamin, recent studies have highlighted the possible danger of over supplementing with it as a single nutrient. Last month University of Southern California researchers reported that people taking about 500 mg of vitamin C daily for a year showed a progression in carotid wall thickness that was 2.5 times greater than those who did not take a vitamin C supplement. No evidence was found that elevated levels of vitamin C from food sources promoted atherosclerosis. Another study, recently reported at the American Cancer Society meeting, concluded that large doses of vitamin C might be harmful to cancer patients because the vitamin may protect their tumors from radiation and chemotherapy treatments. Again, obtaining vitamin C from foods does not pose a danger.
Vitamin C is found in many plant food sources, including oranges, grapefruits, peppers, cantaloupe, strawberries, broccoli, potatoes, kale, cauliflower, tomatoes, dark green vegetables and many other foods. Just 1 cup of orange juice provides about 100mg of vitamin C.
Remember to eat 5-A-Day and you will get plenty of vitamin C!
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