NEW YORK (Reuters) -- Men who have a particular vitamin D receptor gene are less likely than others to develop the type of prostate cancer that requires surgical removal, a recent study suggests.
"Our findings support the hypothesis that vitamin D plays an important role in prostate cancer," wrote lead author Dr. Jack A. Taylor, of the National Institute of Environmental Health Sciences (NIEHS) in Research Triangle Park, in North Carolina.
Previous studies have suggested that lack of sunlight -- which boosts vitamin D -- is linked to prostate cancer, as is having low blood levels of the vitamin. Other reports have found that break-down products of vitamin D can suppress the growth of prostate cancer cells in the laboratory.
"Different men have different risks of prostate cancer," stated Taylor in a release from the NIEHS, "and this could be based, in part, on how their bodies utilize vitamin D."
In the study, researchers looked at 108 cancer patients undergoing surgical removal of the prostate -- the walnut-shaped gland surrounding the urethra -- and compared them with 170 cancer-free men. They found that 22% of the cancer patients had two copies -- one from each parent -- of a particular vitamin D receptor gene, compared with just 8% of the cancer-free patients, according to a report in the journal Cancer Research. Vitamin D influences the body by binding to the receptor in the body.
Two different types of genes make up the receptor, designated by scientists as T, or t. Each individual has two such genes, making them TT, Tt, or tt. In the study, men who were tt were one-third less likely to have prostate cancer.
"If these findings can be verified, (the gene variation) represents an important determinant of prostate cancer risk," Taylor wrote. However, it is not yet clear that increasing consumption of vitamin D-rich food -- such as fortified milk -- can prevent prostate cancer.
"The body's metabolism of vitamin D is complex," Taylor said. "Simply increasing vitamin D consumption or sunlight exposure may not affect levels of the vitamin in the blood."
SOURCE: Cancer Research (1996;4108-4110)
