Barry EL, et al. - Researchers conducted this study to reconcile findings from two of their prior investigations: the Vitamin D/Calcium Polyp Prevention Study (VCPPS; 2004–2013)—a recent randomized controlled trial that reported no significant reduction in colorectal adenomas following calcium supplementation (1,200 mg/day)— and the Calcium Polyp Prevention Study (CPPS; 1988–1996), which reported results contrary to VCPPS. For this purpose, they identified differing participant characteristics between study populations and modified the effect of calcium supplementation on adenomas or high-risk findings (advanced or multiple adenomas). They found that more participants in the VCPPS population were obese and fewer had normal body mass index (BMI) values compared with those in the CPPS population. They observed an attenuated risk of colorectal adenomas with 1,200 mg/day calcium supplementation in those with normal BMI but not in overweight or obese individuals; the apparent difference in calcium efficacy between the two trials was partly attributed to differences in BMI distribution.