Vitamin D research found the supplement can either decrease or increase the risk of breast cancer.
The study, presented at the American Association for Cancer Research in Florida, found vitamin D significantly reduced estrogen receptor-positive breast cancer in lean and obese mice, but found no positive effect on estrogen receptor-negative cancer.
Use of vitaming D supplementation is clearly tricky, said Leena Hilakivi-Clarke, lead investigator and a professor at Georgetown Lombardi Comprehensive Cancer Center, according to UPI. In the many studies that have been done studying the effect of vitamin D in different cancer types, there is no straight link between use and benefits.
Obese mice destined to develop estrogen-receptor negative breast cancer taking vitamin D were worse off than lean ER negative mice.
Hilakivi-Clarke says people should talk to their doctor if they want to increase their intake of vitamin D.
"This is not a vitamin that should be taken lightly," Hilakivi-Clarke said. "People need sufficient amounts because it has beneficial effects for overall health that have nothing to do with preventing cancer.
