Cedric F. Garland of Moores Cancer Center at the University of California, San Diego, says the research team has shown associations between higher levels of vitamin D and lower risk of breast, colon, kidney and ovarian cancers.

"This is the first study, to our knowledge, to show that higher serum levels of vitamin D are associated with reduced risk of endometrial cancer," Garland said in a statement. "Previous epidemiological studies have focused on estrogen levels -- either natural or through hormone replacement therapy -- which play the major role in development of the disease, and on fat intake, which plays a smaller role. Since most women cannot control their natural levels of estrogen, and very low levels of fat intake are not acceptable to most American women, this article provides evidence that vitamin D adequacy should be considered as part of a comprehensive program for prevention of this cancer."

The authors caution that the findings deal with aggregates, or countries, and may not apply to individuals.

The findings are published in the journal Preventive Medicine.