11.   This study assessed the effect of antioxidant vitamin supplementation on colonic crypt cell proliferation in patients with adenomatous polyps of the colon.

12.   Subjects with adenomatous polyps had an increased cell proliferation with an increasing trend of proliferating cells towards the apex of the crypt as has been found by thers.

13.   We recently assessed serum concentrations of vitamin A and E in Irish subjects with adenomatous polyps and colorectal cancer.

14.   Few studies have been carried out assessing the effect of vitamin supplementation on adenomatous polyps or colorectal cancer.

15.   In conclusion this study has shown that both Beta -carotene and vitamin C supplementation reduce the abnormal colonic crypt cell proliferation found in subjects with adenomatous polyps.

16.   This may reduce the risk of progression to carcinoma and the recurrence of adenomatous polyps.

17.   We and others have previously shown increased mucosal cell proliferation in patients with adenomatous polyps or cancer and a reduction of mucosal cell proliferation after calcium supplementation.

18.   Reproducible kinetic parameters such as these might be useful in planning follow up of patients with adenomatous polyps after polypectomy.

19.   These changes may also precede the development of adenomatous polyps.

20.   Our data confirm an upward shift of the proliferative zone in the patients with adenomatous colorectal polyps.