A report in the Journal of the National Cancer Institute says that calcium or vitamin D supplements don’t seem to decrease the risk of invasive breast cancer in postmenopausal women.

Dr. Rowan T. Chlevbowski (from the University of California, Los Angeles) and colleagues note that the results of observational studies associate higher calcium and vitamin D levels with a lower risk of breast cancer, but yet this topic has not been addressed in a different type of trial.

In this study, 36282 women participants randomly received calcium 1000 mg plus vitamin D 400 IU per day or placebo for 7 years to find the effect of these supplements on hip fractures. A secondary endpoint of the study was the supplements’ effect on invasive breast cancer.

The researchers found that there wasn’t any significant difference in the number of patients who developed invasive breast cancer in the supplement group and the placebo group, as it was 528 versus 546.

The initial levels of 25-hydroxyvitamin D levels were analyzed by the researchers in 1,067 women who with breast cancer and in 1067 who didn’t.

The researchers noted that the women who developed invasive breast cancer had similar levels of 25-hydroxyvitamin D levels in the nutrient as in the control group. The researchers didn’t find any correlation between 25-hydroxyvitamin D levels and breast cancer risk after making adjustment in the data for variations in weight and physical activity levels.