Women who combine multivitamins and calcium appear to have a reduced risk of breast cancer development, according to new research findings presented at the American Association for Cancer Research’s annual conference in Washington, DC, and reported by HealthDay News.

For the study, researchers compared the vitamin and calcium intake of 268 women with cancer and 457 without breast cancer. In addition, they measured the women’s DNA repair ability because this function is key to keeping cancer at bay.

Researchers found that taking a multivitamin tablet reduced tumor risk by 30 percent and calcium reduced the risk by 40 percent.

“Which vitamins exactly? We don’t know because they were multivitamins,” said Manuel Bayona, MD, a professor in the public health program at the Ponce School of Medicine in Ponce, Puerto Rico, and a study author.

The findings suggest that calcium’s protective characteristics come mostly from its ability to affect DNA repair. But vitamins seemed to retain benefits beyond that ability.

The study authors are researching ways to use DNA repair capacity to identify breast cancer risk, including developing new technology for inexpensive, faster and easier measuring.

Another expert called the study unconvincing. She suggested that women not rely on multivitamin-calcium cocktails for breast cancer prevention.

Click here to learn about breast cancer screening.