Calcium and vitamin D do not inhibit the growth of normal and transformed intestinal cells

Background: Several lines of evidence suggest a potential role for calcium and vitamin D in colon cancer prevention. Objective: To evaluate the effect of calcium and vitamin D, on the growth of normal and transformed cells. Methods: Cultures of normal and transformed rat intestinal epithelial cells were treated with different dosages of calcium and vitamin D, alone and in combinations. Cell cycle distribution and apoptosis were determined by FACS analysis. Results: Calcium and vitamin D up to a maximal concentration of 4 mM and 1 μM, respectively, did not inhibit cell growth or induce apoptosis. Protein levels of the bcl-2 and cyclin super-families exhibited no change. Sulindac sulfide on the other hand inhibited cell growth and induced apoptosis in a dose-dependent fashion. Conclusions: Normal and transformed enterocytes are not sensitive to high dosages of calcium and vitamin D. Future studies should elucidate their role in growth inhibition and their protective effects.