Indication: Colorectal cancer


Source: Am J Epidemiol, March 22, 2007 [Epub ahead of print]

Research: The authors of this study examined intakes of calcium and vitamin D, and interaction with retinol, in relation to risk of adenoma of the distal colon or rectum among 48,115 U.S. women who were free of colorectal cancer or polyps, completed a food frequency questionnaire in 1980, and underwent endoscopy by 2002.

Results: During years of follow-up, researchers documented 2747 cases of adenoma (1064 large, 1531 small, 2085 distal colon and 779 rectal). Total calcium intake was weakly associated with distal colorectal adenoma risk. Total vitamin D intake was weakly associated with reduced risk of distal colorectal adenoma. The combinations of high vitamin D and low retinol intake further decreased risk of distal colorectal adenoma when compared with the opposite extreme. Researchers concluded that higher total calcium and vitamin D intakes were associated with reduced risk, and the actions of vitamin D may be attenuated by high retinol intake.