A Trial of Calcium and Vitamin D for the Prevention of Colorectal Adenomas
N Engl J Med 2015; 373:1519-1530October 15, 2015DOI: 10.1056/NEJMoa1500409
Overview Cancer-Colon and vitamin D
After 30 years it still appears that vitamin D deals with colorectal cancer – Oct 2012
Colon cancer 30 percent more likely if low vitamin D – 12th meta-analysis Aug 2015
Colon cancer risk reduced by many vitamins – 13 percent reduction by Vitamin D – meta-analysis Jan 2015
Colorectal cancer 26 percent less likely for every 10 ng of vitamin D – meta-analysis Aug 2011
Colorectal Cancer and Vitamin D infographic
BACKGROUND
Epidemiologic and preclinical data suggest that higher intake and serum levels of vitamin D and higher intake of calcium reduce the risk of colorectal neoplasia. To further study the chemopreventive potential of these nutrients, we conducted a randomized, double-blind, placebo-controlled trial of supplementation with vitamin D, calcium, or both for the prevention of colorectal adenomas.
METHODS
We recruited patients with recently diagnosed adenomas and no known colorectal polyps remaining after complete colonoscopy. We randomly assigned 2259 participants to receive daily vitamin D3 (1000 IU), calcium as carbonate (1200 mg), both, or neither in a partial 2×2 factorial design. Women could elect to receive calcium plus random assignment to vitamin D or placebo. Follow-up colonoscopy was anticipated to be performed 3 or 5 years after the baseline examinations, according to the endoscopist’s recommendation. The primary end point was adenomas diagnosed in the interval from randomization through the anticipated surveillance colonoscopy.
RESULTS
Participants who were randomly assigned to receive vitamin D had a mean net increase in serum 25-hydroxyvitamin D levels of 7.83 ng per milliliter, relative to participants given placebo. Overall, 43% of participants had one or more adenomas diagnosed during follow-up. The adjusted risk ratios for recurrent adenomas were 0.99 (95% confidence interval CI, 0.89 to 1.09) with vitamin D versus no vitamin D, 0.95 (95% CI, 0.85 to 1.06) with calcium versus no calcium, and 0.93 (95% CI, 0.80 to 1.08) with both agents versus neither agent. The findings for advanced adenomas were similar. There were few serious adverse events.
CONCLUSIONS
Daily supplementation with vitamin D3 (1000 IU), calcium (1200 mg), or both after removal of colorectal adenomas did not significantly reduce the risk of recurrent colorectal adenomas over a period of 3 to 5 years. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00153816.)