By Hong Mautz

Aug. 22 (CBSHealthWatch) -- Vitamin D, an essential nutrient for building strong bones and teeth, may also play a significant role in cancer prevention, according to a new study.

Previous research has shown that vitamin D compounds slowed tumor growth in prostate cancer and colon cancer. But researchers say that it has been associated with the side effect hypercalcemia -- the excessive accumulation of calcium in the blood that can lead to morbidity and mortality.

Using specially designed vitamin D, researchers found that the compounds were able to reduce tumor formation.

"These new chemical entities have initial profiles that are promising as drug candidates," says Dr. Gary Posner, principal investigator of the study and Scowe Professor of chemistry at Johns Hopkins University in Baltimore, Maryland. "Typically, it takes ten years for a drug to hit the market."

Researchers administered a cancer-producing carcinogen to mice. One group of mice received vitamin D compounds, and the control group did not. "The best of our compounds were able to delay tumor formation significantly," says Posner. "The compound did not disturb the calcium balance in the animals."

After a 20-week treatment period, the most promising vitamin D candidate reduced the incidence of tumors by 28% and the number of tumors by 63%.

Posner cautions that the study is at a very early stage and that it only focused on skin cancer in mice. "Larger types of animals such as rats and dogs will have to be tested as well as different cancers," says Posner. "Clearly, there is a whole series of hurdles to jump over. But this is the first live animal verification that this class of compounds are potent and safe."

Other experts say the significance of the study is that researchers took a vitamin D molecule and modified it so it has anti-cancer activity but does not affect calcium metabolism.

"One of the biggest problems with high levels of vitamin D is that it causes hypercalcemia," says Dr. Susan Fischer, professor of carcinogenesis at the University of Texas M. D. Anderson Cancer Center in Smithville, Texas. "They were able to get rid of that part of the function of the Vitamin D molecule and keep the anti-(cancer) part."

Fischer says that more studies are apparently needed to look at different animal models and different types of cancers. But she says the implication could be that vitamin D might prove to be an effective way to prevent a number of cancers including prostate cancer and colon cancer.

The findings are presented today at the 220th national meeting of the American Chemical Society in Washington, DC. The study also appears in the August issue of Carcinogenesis.

　　(From AOL.com)