Date: Wed, 23 Aug 2000 18:17:52 -0700 (PDT)

CNN Interactive

August 22, 2000 Web posted at: 5:45 p.m. EDT (2145 GMT)

Vitamin D being studied as anti-cancer drug

WASHINGTON (CNN) -- Early studies show vitamin D is successful in reducing the risk of cancer, researchers at Johns Hopkins reported Tuesday.

Besides keeping bones strong, vitamin D is also very effective at controlling cell growth, the researchers said at a meeting of the American Chemical Society.

Because the vitamin is toxic in high doses, taking calcium from the bone and moving it to the blood and urine, scientists had to alter the vitamin for the trials. The natural vitamin would not be safe at the dosage researchers believe would be necessary for cancer prevention.

The Hopkins researchers designed four different versions of vitamin D in the laboratory and tested them on two groups of mice: one painted with a tumor-inducing chemical, and one that was not. After 20 weeks, the most promising version of the vitamin had reduced the incidence of tumors by 28 percent and the number of tumors by 63 percent.

Dr. Gary Posner, one of the Hopkins researchers, said they are not sure why the altered vitamin performs differently from the natural version, retaining the benefits and none of the drawbacks of natural vitamin D.

The next step, the scientists said, is to study the compound in bigger animals and with other cancers. It will be several steps yet before the compound can be tested in humans.

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