 We assert that using biological measurements of risk, as they have for ischemic heart disease, will result in a decline in colorectal cancer incidence and mortality. The proposed project is borne of this vision, and has intertwined missions of exploring the efficacy of two plausible and evidentially well-supported dietary agents, calcium and vitamin D, on the modulation of a plausible panel of molecular phenotypic biomarkers of risk for colorectal neoplasia. 