Daily supplementation with vitamin D3, calcium, or both following the removal of colorectal adenomas, benign precursor lesions of colorectal adenocarcinoma, did not significantly reduce the risk of recurrent adenomas over a 3- to 5-year period, a new study published this week in The New England Journal of Medicine has shown.1

Because preclinical data have suggested that higher intake of vitamin D and calcium reduce the risk of colorectal neoplasia, researchers sought to evaluate whether vitamin D, calcium, or both prevent colorectal adenomas.

For the double-blind, placebo-controlled trial, researchers enrolled 2,259 patients with recently diagnosed adenomas and no known colorectal polyps remaining after undergoing a complete colonoscopy.

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Participants were randomly assigned to receive daily vitamin D3 1,000 IU, calcium carbonate 1,200 mg, both, or neither. Women were eligible to elect to receive calcium in addition to random assignment to vitamin D or placebo.

Results showed that 43% of all participants had at least one adenoma diagnosed during follow-up colonoscopy 3 to 5 years after baseline examinations.

Researchers found that there was no significant difference in the risk for recurrent adenomas or recurrent advanced adenomas between the four treatment arms. In regard to safety, few serious adverse events occurred.


1. Baron JA, Barry EL, Mott LA, et al. A trial of calcium and vitamin D for the prevention of colorectal adenomas. N Engl J Med. 2015;373:1519-1530.