Calcium and vitamin D lowered risk for breast cancer and weight gain in women, in two new studies.
In a breast cancer risk study, researchers enrolled more than 31,000 pre- and post-menopausal women, average age 55, who were slightly overweight, in a 10-year study looking at the effect of calcium and vitamin D on breast cancer risk. When the women enrolled, none had cancer or cardiovascular disease. Researchers evaluated the diets, medical histories and lifestyles of the women. During the 10-year follow-up period, about 3 percent of pre-menopausal women and 4 percent of post-menopausal women developed breast cancer. For pre-menopausal women, doctors found that compared to those who consumed the lowest levels of calcium or vitamin D, those who consumed the most calcium were 39 percent less likely to develop breast cancer and those who consumed the most vitamin D were 35 percent less likely to develop breast cancer. Study authors noted that in pre-menopausal women, as calcium or vitamin D levels increased, the risk of developing more aggressive tumors decreased. Risk for breast cancer did not vary with calcium or vitamin D levels in post-menopausal women.
In a weight study, more than 36,000 post-menopausal women aged 50 to 79 took 1,000 mg of elemental calcium plus 400 IU of vitamin D per day or a placebo. After seven years, women who had taken calcium and vitamin D weighed on average about a quarter-pound less than women who had taken the placebo, which doctors described as a small but consistent improvement. Women in the calcium-vitamin D group who reported getting too little calcium before the study weighed about a half-pound less on average than women in the placebo group.