Study: Vitamin C Pills May Damage DNA

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Study: Vitamin C Pills May Damage DNA

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Study: Vitamin C Pills May Damage DNA

By Recer

AP Science Writer

Thursday, June 14, 2001; 2:01 p.m. EDT

WASHINGTON –– Vitamin C pills, popped by millions as a protection

against colds and other diseases, actually may play a role in damaging

DNA, a step toward forming cancer cells, a laboratory study suggests.

In a test tube experiment analyzing the action of vitamin C, University of

Pennsylvania researchers found that the nutrient can act as a catalyst to

help make a toxin that wounds DNA, the body's genetic code. The study

appears Friday in the journal Science.

The findings do not mean that vitamin C causes cancer, said Ian A. Blair,

lead author of the study, but the research does sound a warning about the

use of vitamin C pills.

" Vitamin C can do some good things, but it can do some bad things as

well, " Blair said. " If you really wanted to be cautious, you just

wouldn't use supplementation (vitamin pills.) "

....

Balz Frei, a professor at the Linus ing Institute at Oregon State

University, said the Blair study " is an important finding in understanding

the

chemistry of Vitamin C. " But he cautioned that the results come from a

test tube study, which involves chemicals in glass lab dishes, and that the

same action may not occur in living animals.

....

Blair said his group found that vitamin C was highly efficient in

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 for lesions in the

DNA. "

But Blair said the research may explain the failure of studies that have

attempted to show vitamin C can protect against cancer.

....

Vitamin C is an antioxidant. It neutralizes oxygen free radicals, which

are metabolic products in the cell that can damage DNA. Some researchers

have speculated that because of its antioxidant action, large doses of

the vitamin could prevent cancer, strengthen the immune system and prevent

the common cold.

....

Vitamin C can help patients lower high blood pressure, and Frei said

some studies have suggested that " people in a disease state, " such as an

infection, may be helped by vitamin C.

But when asked if healthy people benefit from vitamin C pills, he noted:

" I don't think we could say that. "

The Institute of Medicine, an arm of the National Academy of Sciences,

recommends that women need 75 milligrams of vitamin C daily and 90

milligrams for men. Smokers need an additional 35 milligrams. These are

levels easily achieved by a balanced diet.

Much more than that is generally useless, said Frei. A healthy body can

absorb about 200 milligrams a day and the surplus is carried away with

the urine.