THE EFFECT OF CALCIUM SUPPLEMENTS ON RECTAL MUCOSAL PROLIFERATION

Seventy-nine patients with colorectal adenomata were randomised to rec eive calcium carbonate (3,000 mg) or placebo in a double-blind randomi sed trial to assess the short- and long-term effects on rectal mucosal proliferation measured by the in vitro metaphase arrest technique cry pt cell production rate (CCPR). There was no significant difference in mean CCPR between the groups before treatment or after 3 or 12 months . In those patients randomised to calcium, CCPR fell at both 3 months [9.0 (2.8) cc c(-1) h(-1), t = 3.15, d.f = 76, P = 0.002] and 12 month s [9.2 (3.3) cc c(-1) h(-1) t = 2.7, d.f = 74, P = 0.009] compared wit h pretreatment CCPR [12.2 (5.5) cc c(-1) h(-1)]. We have demonstrated that calcium had no effect on mucosal proliferation compared with plac ebo. The results on adenoma formation are awaited.