Georgetown University researchers suggest obese women can reduce their risk of endometrial cancer by taking vitamin D supplements.Scientists from Georgetown's Lombardi Comprehensive Cancer Center recently showed that 67 percent of obese mice fed a regular diet developed this cancer, versus only 25 percent of obese mice fed a vitamin D-supplemented diet. “In the obese mice, vitamin D offered a very strong, very significant protective effect,” says the study's lead investigator, professor of oncology Leena Hilakivi-Clarke. The findings, published in Cancer Prevention Research, also reported that vitamin D offers no protective effects for mice of normal weight. About 60 percent of mice predisposed to endometrial cancer developed it no matter what diet they were fed.
All of the mice in the study were genetically predisposed to develop endometrial cancer because they lacked one of two tumor suppressor genes. People without one of these genes are strongly predisposed to the cancer, and obesity adds a strong risk factor for the disease, researchers say. “Vitamin D has been shown to be helpful in a number of cancers, but for endometrial cancer, our study suggests it protects only against cancer that develops due to obesity,” Hilakivi-Clarke says. “Still, if these results are confirmed in women, use of vitamin D may be a wonderfully simple way to reduce endometrial cancer risk.”
Until further studies are conducted, she says women concerned about their risk of this disease may wish to take vitamin D supplements or spend a few more minutes each week in the sun, They also should strive to lose weight if they are carrying around too many pounds. The National Cancer Institute and the Department of Defense funded the research, which also included investigators from the National Cancer Institute, Northwestern University, Wake Forest University School of Medicine and Walter Reed Hospital.
“But we really don't know why dietary vitamin D works so well in our obese mice,” Hilakivi-Clarke says. “We are currently investigating the mechanisms, and we are hopeful that we can find an answer.”