HealthDay (11/11, Gordon) reported that, "although calcium and vitamin D may keep your bones strong, these vital nutrients don't appear to help postmenopausal women lower their risk of breast cancer,"

According to a study expected to be published Nov. 19 in the Journal of the National Cancer Institute. The study of patients with no breast-cancer history "was a double-blind, placebo-controlled trial that included 36,282 postmenopausal women." Powel Brown, director of the cancer prevention program at the Lester and Sue Smith Breast Center at Baylor College of Medicine in Houston, encouraged further investigation, and "said that, although the current study was very well-done, he doesn't think that researchers 'can definitively say that vitamin D isn't helpful for the prevention of breast cancer.'"

USA Today (11/12, Szabo) adds, "In their paper," the "authors say it's possible that the women didn't take the supplements long enough, given that cancer can take decades to develop." In addition, the authors "note that they also don't know the effect of taking either calcium or vitamin D alone, because women in the study took them together."  "The women were followed for seven years, on average," 

WebMD (11/11, Hitti) reported. Over the years, "similar numbers of women in each group developed breast cancer."  

According to the Los Angeles Times (11/12, Kaplan), "Over the course of the study, 528 of the 18,176 women, or 2.9 percent, who got the combined pill developed invasive breast cancer, compared with 546 of the 18,106 who got the placebo, or 3.0 percent." The Times notes that other studies have suggested the daily dose of vitamin D "should be between 1,000 and 2,000 IUs per day, well above the amount used in this trial." In addition, Brown noted the supplements "might also prove valuable to premenopausal women."