A Trial of Calcium and Vitamin D for the Prevention of Colorectal Adenomas.

Study answer

What this study found

Daily vitamin D3, calcium, or both did not significantly reduce recurrent colorectal adenomas or advanced adenomas in this population. For any adenoma, the adjusted risk ratio was 0.99 (95% CI, 0.89 to 1.09) for vitamin D versus no vitamin D and 0.95 (95% CI, 0.85 to 1.06) for calcium versus no calcium. Vitamin D plus calcium also showed no benefit versus calcium alone (risk ratio, 1.01; 95% CI, 0.88 to 1.15) or versus neither agent (risk ratio, 0.93; 95% CI, 0.80 to 1.08). Contingency-table comparisons were likewise nonsignificant: P = 0.98, P = 0.37, P = 0.79, and P = 0.49, respectively.…

Study & population

This was a randomized multicenter trial conducted at 11 academic medical centers and associated practices in the United States.

Intervention

Participants took oral vitamin D3 1000 IU daily, calcium carbonate 1200 mg daily, both agents together, or matched comparators in a 2-by-2 factorial regimen.

Key limitation

The vitamin D dose was relatively modest, which may have limited efficacy detection.

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Original abstract