Vitamin D's Role in Suppressing Cancer

Vitamin D has been shown to inhibit the spread of prostate cancer cells by restricting the activity of two specific enzymes, according to new research.

This discovery means that vitamin D could provide beneficial treatment to prostate cancer patients with high levels of the enzymes, according to the researchers. "We wanted to know the targets of vitamin D so we would know which patients would respond better,” said Yi-Fen Lee, Ph.D., an assistant professor of urology and lead investigators from the University of Rochester Medical Center (NY, USA). The investigators published their study in the January 2006 issue of the journal Carcinogenesis. The study was performed in test tubes using human prostate cancer cells lines.

An estimated 232,000 new cases of prostate cancer were diagnosed in the United States lain 2005--more than any other cancer in men. Approximately 30,000 deaths occurred from prostate cancer in the United States last year.

Recent evidence from studies increasingly has indicated that vitamin D suppresses the progression of cancer. The scientists found that vitamin D considerably limits the ability of prostate cancer cells to invade healthy cells by reducing the activity of two enzymes--proteases called matrix metalloproteinase and cathepsin. Vitamin D also increases the level of corresponding enzymes that suppress matrix metalloproteinase and cathepsin, the scientists found. Vitamin D, however, had little effect on plasminogen activators, which also are important in the spread of prostate cancer. "Each individual is different so the therapy could be custom made for each person,” Dr. Lee said.

The vitamin D used in the study is 1,25-hydroxylvitamin D3, the strongest and most active form of vitamin D in the human body. But Dr. Lee and other coworkers do not recommend taking large amounts of vitamin D without medical supervision. "This high dose has some side effects, including increasing blood calcium levels and causing kidney problems,” said Edward M. Messing, M.D., chair of urology at the Medical Center. "It should not be taken without prescription and a physician monitoring the side effects.”

Dr. Lee is studying whether there are medications or other vitamins, such as vitamin E, that could enhance the anti-cancer effects of vitamin D without increasing toxicity. "The best way to get vitamin D is to drink milk, get modest exposure to the sun, and take a vitamin pill to enrich the vitamin D, which might prevent cancer,” Dr. Lee said.



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University of Rochester Medical Center