ABSTRACT
This chapter investigates the effects of calcium on rectal mucosal proliferation assessed by tritiated thymidine labeling indices in to randomized, double-blind, controlled trials. It investigates the effects of supplemental calcium in two groups of patients at high risk for colorectal cancer. The chapter examines a group of patients with familial polyposis coli having undergone a subtotal colectomy and ileorectal anastomosis. Some epidemiologists have suggested that high dietary levels of calcium are associated with low risk of colon cancer, though others consider that this association is not yet established. Compliance to the assigned regimen was assessed by pill count and measurement of calcium concentration in the aqueous phase of stools. The study protocol was approved by the Human Subject Committee of the University of Toronto. The results of the study both complement and contrast with earlier studies with calcium supplementation. That randomized control trial also failed to demonstrate an effect of calcium supplementation on colonic proliferation patterns.
