Indication: Breast Cancer


Source: Arch Intern Med, May 28, 2007; 167(10):1050-9.

Research: Researchers prospectively evaluated total calcium and vitamin D intake in relation to breast cancer incidence among 10,578 premenopausal and 20,909 postmenopausal women 45 years or older who were free of cancer and cardiovascular disease at baseline in the Women’s Health Study. Baseline dietary intake was assessed using a food frequency questionnaire.

Results: During an average of 10 years of follow-up, 276 premenopausal and 743 postmenopausal women had a confirmed diagnosis of incident invasive breast cancer. Higher intakes of total calcium and vitamin D were moderately associated with a lower risk of premenopausal breast cancer. The inverse association with both nutrients was also present for large or poorly differentiated breast tumors among premenopausal women. By contrast, intakes of both nutrients were not inversely associated with the risk of breast cancer among postmenopausal women. The one-fifth of premenopausal women who consumed the highest levels of calcium and vitamin D—nearly 1400 mg and 1000 units of calcium and vitamin D, respectively—reduced their risk by 30% compared with those women consuming the least amounts of calcium and vitamin D. In analyzing these results, researchers believe that higher intakes of calcium and vitamin D may be associated with a lower risk of developing premenopausal breast cancer. The likely apparent protection in premenopausal women may be more pronounced for more aggressive breast tumors.