Compared to participants with high 25(OH)D and low IGF-1/IGFBP-3 ratio (reference group), participants with a high IGF-1/IGFBP-3 ratio were at elevated risk of colorectal and colon cancers when 25(OH)D was low (colorectal: odds ratio (OR): 2.05 (95% CI: 1.43 to 2.92), colon: OR: 2.26 (95% CI: 1.48 to 3.47) but not when 25(OH)D was high (colorectal: OR: 1.20 (95% CI: 0.84 to 1.71, p(interaction): additive  = 0.06, multiplicative  = 0.25, colon: OR: 1.27 (95% CI: 0.84 to 1.94), p(interaction): additive  = 0.20, multiplicative  = 0.55), Table 3). This evidence concerns the gene IGF1 and colonic neoplasm.