VDR and rectal cancer: A significant 40% reduction in risk of rectal cancer was observed for the low-activity-associated homozygous VDR LL or bb genotypes when calcium intake was high (OR: 0.56, 95% CI: 0.36–0.85) (reference: homozygous VDR LL or bb genotypes and low calcium intake), whereas the observed risk for the homozygous SS or BB genotypes did not depend on calcium intake (P-interaction 0.01).