Vitamin C Pills May Injure DNA

W A S H I N G T O N, June 14 -- The vitamin C pills taken by millions of health-conscious people may actually help produce toxins that can damage their DNA, a step toward forming cancer cells, a laboratory study suggests.

In a study appearing Friday in the journal Science, Universityof Pennsylvania researchers said they found in test tubeexperiments analyzing the action of vitamin C that the nutrient canact as a catalyst to help make a toxin that can injure DNA, thebody's genetic code.

The findings do not mean that vitamin C causes cancer, said IanA. Blair, lead author of the study, but the research does sound awarning about the use of vitamin C pills.

"Vitamin C can do some good things, but it can do some badthings as well," Blair said. "If you really wanted to becautious, you just wouldn't use supplementation [vitamin pills]."

Instead of pills, Blair said people can get all the nutrientsthey need through a balanced diet, particularly fruits, vegetablesand grains.

Understanding Vitamin C

Balz Frei, a professor at the Linus Pauling Institute at OregonState University, said the Blair study "is an important finding inunderstanding the chemistry of vitamin C." He cautioned that theresults come from a test tube study, which involves chemicals inglass lab dishes, and that the same action may not occur in livinganimals.

In the study, Blair and his colleagues analyzed the effects ofvitamin C on lipid hydroperoxide, a compound produced in the bodyfrom fat in the diet. Lipid hydroperoxide can be converted in thecell into agents, called genotoxins, that can damage DNA.

Blair said his group found that vitamin C was highly efficientin converting lipid hydroperoxide into the gene-damaging toxins.

"Just because you damage DNA doesn't mean you'll get cancer,"Blair said. "The cell has an exquisite repair mechanism forlesions in the DNA."

Blair said the research may explain the failure of studies thathave attempted to show vitamin C can protect against cancer.