Background: Recent attention has focused on calcium and certain vitamins as potential protective agents against colorectal neoplasia.
Methods: Two case-control studies were conducted on patients who underwent colonoscopy between 1986 and 1988, comparing 297 patients with newly diagnosed adenomas with 505 controls (without current or prior history of neoplasia), and 198 patients with recurrent adenomas with 347 recurrent controls (with no current neoplasia, but with a history of polypectomy). Subjects were interviewed regarding their regular usage of supplementation with vitamins A, C, D, and E, or with calcium, multivitamins, or any vitamin supplements.
Results: No consistent associations were observed with the use of any of these supplements.
Conclusions: More studies are necessary to confirm these findings. It may be necessary to develop other chemopreventive agents, such as aspirin, for colorectal neoplasia.