Sunshine May Provide Prostate Protection
Prostate Cancer Risk Linked to Vitamin D From Sunlight
Vitamin D Detective Finds Prostate Cancer Clue continued...
Moreover, Schwartz notes that prostate cells are able to process vitamin D. In fact, the surface of a prostate cell bears a molecule called a vitamin D receptor or VDR. When vitamin D plugs into one of these receptors, it sets off a complex chain of events thought to protect the cell against cancer.
But when other researchers looked at whether sun exposure and vitamin D levels were linked to prostate cancer, they got mixed results. Some found a link. Others did not. Clearly, something else is going on.
Sun Exposure and Prostate Cancer
John, Brooks, and colleagues decided not to take a one-time measure of vitamin D levels or to rely on people's estimates of sun exposure. They used a device to compare skin pigmentation on a person's exposed skin to pigmentation on that person's unexposed skin. They then calculated that person's sun exposure.
The researchers studied 450 non-Hispanic white Americans with prostate cancer and compared them with 455 similar men without prostate cancer.
The bottom line: Those with high sun exposure were 49% less likely to have prostate cancer.
The researchers also got blood samples from study participants. They looked for vitamin D receptor genes.
People who carried genes for particularly effective vitamin D receptors were 54% to 33% less likely to have prostate cancer, depending on the gene involved.
All this is very interesting to cancer researcher Jay Brooks, MD, chief of hematology/oncology at the Ochsner Clinic in Baton Rouge, La.
"These are very interesting and intriguing observations," Brooks tells WebMD. "One interesting thing is the vitamin D aspect. Another thing is the cancer risk reduction with certain genes of an individual. We are beginning to look at genetic markers that predict a risk of certain cancers. In terms of prostate cancer, hopefully we will soon have improved medicines to reduce the risk of cancer in these individuals."
Brooks warns that the current study does not prove vitamin D deficiency causes prostate cancer. It's too soon, he says, for people to start taking vitamin D in hopes of cutting their risk.