Data from Meta-Analyses of Vitamin D Intake, 25-Hydroxyvitamin D Status, Vitamin D Receptor Polymorphisms, and Colorectal Cancer Risk

<div>Abstract<p><b>Background:</b> Our objective was to conduct a systematic review and meta-analysis of prospective studies on colorectal cancer (CRC) and vitamin D intake and 25-hydroxyvitamin D status, as part of the World Cancer Research Fund Continuous Update Project. We also aimed at conducting meta-analysis of all studies on CRC and vitamin D receptor (<i>VDR</i>) single-nucleotide polymorphisms.</p><p><b>Methods:</b> Relevant studies were identified in PubMed (up to June 2010). Inclusion criteria were original and peer-reviewed publications with a prospective design (for studies on vitamin D intake or status). Random effects of dose-response meta-analyses were performed on cancer incidence.</p><p><b>Results:</b> We observed inverse associations of CRC risk with dietary vitamin D [summary relative risk (RR) per 100 IU/day = 0.95, 95% CI: 0.93–0.98; 10 studies; range of intake (midpoints) = 39–719 IU/day] and serum/plasma 25-hydroxyvitamin D (RR per 100 IU/L = 0.96, 0.94–0.97; 6 studies; range = 200–1,800 IU/L), but not with total vitamin D (5 studies). Supplemental (2 studies; range = 0–600 IU/day) and total (4 studies; range = 79–732 IU/day) vitamin D intake and 25-hydroxyvitamin D status (6 studies; range = 200–1,800 IU/L) were inversely associated with colon cancer risk. We did not observe statistically significant associations between <i>FokI</i>, <i>PolyA</i>, <i>TaqI</i>, <i>Cdx2</i>, and <i>ApaI VDR</i> polymorphisms and CRC risk. The <i>BsmI</i> polymorphism was associated with a lower CRC risk (RR = 0.57, 0.36–0.89 for BB versus bb, 8 studies).</p><p><b>Conclusions:</b> These meta-analyses support the evidence of an inverse association between vitamin D intake, 25-hydroxyvitamin D status, and the <i>BsmI VDR</i> polymorphism and CRC risk.</p><p><b>Impact:</b> Improving vitamin D status could be potentially beneficial against CRC incidence. <i>Cancer Epidemiol Biomarkers Prev; 20(5); 1003–16. ©2011 AACR</i>.</p></div>