Various studies in the recent past offered the suggestion that one’s risk of breast cancer may drop when taking vitamin D and calcium supplements. According to the newly released results of a more in-depth exploration of the supplement/breast cancer link, however, the supplements just don’t work.

Researchers at the Los Angeles Biomedical Research Institute at Harbor-University of California Los Angeles Medical Center, led by Rowan Chlebowski, MD, PhD, tapped into the Women’s Health Initiative, a study involving 36,282 postmenopausal women, some of whom were randomly assigned daily doses of a vitamin combo - 1,000 milligrams (mgs) of calcium and 400 International Units (IU) of vitamin D - while the others took daily placebos.

From this pool of study participants, 1,067 women with breast cancer were enlisted for secondary study and 1,067 women without breast cancer were enlisted as control subjects. Each woman’s baseline vitamin D level was determined at the outset of the study.

By study’s end, 528 women taking the daily calcium/vitamin D combo had developed invasive breast cancer, as had 546 women taking placebos, numbers too close to be statistically significant. This lack of evidence of risk reduction when taking these supplements led the research team to conclude no “causal relationship” between the two.

Further findings indicate a strong association between baseline vitamin D levels and leaner women enjoying high levels of physical activity. Both leanness and ample physical activity are associated with reduced risk of breast cancer.

The current issue of the ‘Journal of the National Cancer Institute’ carries the full report.

Source: Journal of the National Cancer Institute