Several recent scientific studies show that there is an inverse relationship between intake of calcium and vitamin D and the risk a premenopausal woman has of developing breast cancer. In other words, women who have a higher intake of calcium and vitamin D, both in their diets and through supplement use, have a lower risk of developing breast cancer.

There have been a variety of studies, including one by Harvard University and the Women’s Health Study. The latter study included 10,578 premenopausal and 20,909 postmenopausal women from the Women’s Health study who completed questionnaires regarding lifestyle, medical history, and food frequency.

There were 131 items in the food frequency questionnaire. Average intake was evaluated using 9 potential responses which ranged from “6 or more times daily” to “less than once per month or never.” Participants also reported their use of calcium supplements and multivitamins and made note of the duration and dosage of these supplements.

The authors found that dairy products accounted for 53% and 395 of total calcium and vitamin D intakes, respectively, while supplements made up 22% and 30% of intakes, respectively. The average daily intake of calcium was 1,021 mg/day, while that of vitamin D was 353 IU/day.

Participants were followed for an average of 10 years. During this time, 276 premenopausal and 743 postmenopausal women developed invasive breast cancer.
Among the women in this study, the premenopausal women with the highest intake of calcium and vitamin D had close to a 40% lower risk of develop breast cancer compared to their study counterparts with the lowest intake of these nutrients. However, this same trend was not seen in postmenopausal women. As a matter of fact, there was no statistically significant association between breast cancer and a higher intake of calcium and vitamin D among women who had gone through the menopause. The famous saying, “Milk, it does a body well,” means more today than it did in the past.

October is breast cancer awareness month and we should all make a special effort to fight this deadly disease. There are so many things that we can do. Simply spreading the word about the decreased risk of breast in premenopausal women with a high intake of calcium and vitamin D has the potential to save lives.

While the simple mention of the words “breast cancer” strike fear deep in the hearts of millions of women, our best defense may be our well thought out offense. We can do all we can to prevent the disease, or at least catch it early. We can, and should, also make educating others about this disease a top priority. Words really can save live.

Author's Bio: 

Dr. A. Maria Hester is a board certified internist, author, and health advocate. She is also the founder of, a unique health empowerment web site.