In addition to protecting themselves from an increased risk of osteoporosis, women who consume relatively high amounts of calcium and vitamin D may also be reducing the risk of premenopausal breast cancer.
In research published in the the May 28, 2007 issue of Archives of Internal Medicine, Jennifer Lin, PhD and colleagues at Brigham and Women's Hospital and Harvard Medical School utilized data from 10,578 premenopausal and 20,909 postmenopausal participants in the Women's Health Study. Medical history and lifestyle questionnaires were completed by the subjects upon enrollment, and dietary questionnaires provided information concerning calcium and vitamin D intake. Subsequent breast cancer diagnoses were reported in yearly follow-up questionnaires.
Over the ten year follow-up period there were 276 premenopausal and 743 postmenopausal women diagnosed with breast cancer. A greater intake of calcium and vitamin D had a protective association against breast cancer in premenopausal, but not postmenopausal women. Premenopausal women whose intake of calcium was in the top one-fifth of participants experienced a 39 percent lower risk of developing breast cancer than women whose intake was in the lowest fifth. For vitamin D, the risk was 35 percent lower for women whose intake was in the top group. The protective association appeared to be greater for more aggressive tumors.
In their commentary concerning the findings, the authors suggest that it is "possible that the protective effects of calcium and vitamin D against postmenopausal breast cancer occur only when intakes of both nutrients are substantially high, as inadequacy of both nutrients is very common in postmenopausal women."
"Further investigation is warranted to study the potential utility of calcium and vitamin D intake in reducing the risk of breast cancer," they conclude.
Reprinted with exclusive permission of Life Extension.