Calcium and vitamin D may promote colorectal health

Supplements of calcium and vitamin D offer potential protection from tumor development in colon and rectum, a new study says.

The researchers randomly assigned 92 men and women with a history of non-malignant (benign) colorectal tumors to receive daily calcium (2.0 g) and/or vitamin D3 supplements (800 IU), or placebo for six months (1). Markers of the health of cells in the colon and rectum were found to increase by 201, 242, and 25 percent in the calcium, vitamin D, and calcium plus vitamin D groups relative to the placebo.

The results support further investigation of calcium and vitamin D as chemopreventive agents against colorectal cancer, the scientists commented.

The potential benefits for the vitamin-mineral combination in relation to colorectal cancer is somewhat controversial, with some studies reporting benefits while others report no results: in 2006, results from the Women's Health Initiative (WHI) stated that daily supplements of vitamin D and calcium 'had no effect' on the risk of colorectal cancer. The results were questioned however and independent cancer experts said at the time that the claims should be interpreted in the light of the complexities of the study with several potential confounders.

Colorectal cancer remains one of the most curable cancers if diagnosis is made early.

1. Fedirko V et al. Effects of Vitamin D and Calcium on Proliferation and Differentiation In Normal Colon Mucosa: a Randomized Clinical Trial. Cancer Epidemiology, Biomarkers & Prevention. 2009; 18:2933–2941.