Because of its popularity and widespread use as a dietary supplement, Vitamin C may be more familiar to the general public than any other nutrient. Studies show that more than 40% of older Americans take Vitamin C supplements. In some regions of the country, almost 25% of all adults, regardless of age, take vitamin C. Outside of a multivitamin, vitamin C is also the most popular supplement among some groups of registered dietitians, and 80% of the dietitians who take vitamin C take more than 250 milligrams.



Vitamin C also called ascorbic acid, is a term that literally means ?no scurvy.? Some 250 years ago, a British physician found that sailors given citrus fruits were cured of scurvy which is the result of a vitamin C deficiency. Dehydroascorbic acid and ascorbic acid are the active forms of vitamin C found in food. Most supplements contain only ascorbic acid. Levels of ascorbic acid in the blood rise to the same degree following the consumption of both vitamin C containing foods and ascorbic acid.

Because of its role in collagen formation and other life-sustaining functions, vitamin C serves as a key immune system nutrient and a potent free-radical fighter. This double-duty nutrient has been shown to prevent many illnesses, from everyday ailments such as the common cold to devastating diseases such as heart disease.

Physicians are often asked whether or not vitamin C is also an effective way of fighting cancer. While there is a growing body of scientific evidence to suggest that vitamin C is useful in the prevention of cancer, the jury is still out on its effectiveness as a cancer treatment. However, its low cost and astonishing lack of toxicity make it an extremely attractive candidate for further testing.

One of the current investigations underway regarding vitamin C's role in the treatment of cancer is led by the Dr. Kedar Prasad, professor of radiology at the University of Colorado Health Sciences Center, Denver. Prasad has demonstrated that vitamin C is capable of inhibiting the growth of cancer cells in vitro. He advocates giving vitamin C and other antioxidants to patients while they are undergoing conventional chemotherapy and radiation. Another team led by Dr. Mark Levine from the National Academy of Sciences studied vitamin C and cancer cells in a series of lab tests. Vitamin C appeared to boost production of hydrogen peroxide which killed cancer cells and left healthy cells unharmed. The levels of vitamin C were so high that they could only be achieved through IV infusions. These findings give plausibility to IV ascorbic acid in cancer treatment, and have unexpected implications for treatment of infections where hydrogen peroxide may be beneficial.

Cancer experts said the ?overwhelming? evidence still suggested vitamin C was not an effective treatment. Studies during the '70s first suggested the administration of high doses of vitamin C could help treat cancer, but later research did not back this up. There are many substances that have been shown to kill cancer cells in the lab but failed to fulfill that promise when tested in people says Henry Scowcroft of UK-based Cancer Research, Inc. In the latest study, published in the Proceedings of the National Academy of Sciences, researchers conducted laboratory experiments which simulated clinical infusions of vitamin C on a range of nine cancer and four normal cells. In five of the cancer lines, there was a 50% decrease in cell survival, while normal cells were unaffected.

Vitamin C's benefits are continually in question but one thing is for sure though, that eating a healthy, balanced diet, including plenty of fresh fruit and vegetables, is an effective way to reduce the risk of getting cancer in the first place.