Friday, November 14, 2008

Calcium and vitamin D do not prevent breast cancer

Previous studies have reported vitamin D supplements may reduce breast cancer risk but a new study, published online in the Journal of the National Cancer Institute, found that calcium and vitamin-D supplements do not reduce breast cancer incidence in postmenopausal women.

More than 36,000 postmenopaused women were randomly assigned to take 1000 mg of calcium plus 400 IU of vitamin D daily or placebo. Researchers found that the incidence of breast cancer was similar in the supplement ( 528) and placebo ( 546) groups. The authors concluded that " the main findings do not support a causal realtionship between calcium and vitamin D supplement use and reduced breast cancer incidence".

In an accompanying editorial "Breast Cancer Prevention Using Calcium and Vitamin D: A Bright Future?" ( free f/t), the authors say that the study results may have been affected by multiple "important confounders" and that vitamin D and calcium may still have a "bright future" in breast cancer prevention and further studies will be needed.

Source: "Calcium Plus Vitamin D Supplementation and the Risk of Breast Cancer" Journal of the National Cancer Institute. Advance Access published online on November 11, 2008 JNCI, doi:10.1093/jnci/djn360

No comments: