Vitamin D intake,serum Vitamin D levels,and risk of gastric cancer: A systematic review and meta-analysis

Background: we are aware of no systematic review or meta-analysis of published findings about the association between vitamin d status and risk of gastric cancer (gc). we systematically reviewed the current evidence on the association between vitamin d intake as well as serum 25-hydroxy vitamin d (25(oh)d) levels and risk of gc. materials and methods: published evidence in this area was searched to august 2014 through the use of isi web of science,scopus,pubmed/medline,ovid database,embase,and google scholar for relevant articles by cross-referencing. seven articles had reported odds ratios (ors) or relative risks (rr) as their effect size; four papers had reported the ors between vitamin d intake and gc; and three papers had reported the association between serum 25(oh)d and risk of gc. results: pooled effect size for comparison of highest versus lowest intakes of vitamin d was 1.09 (95% confidence interval [ci]: 0.94,1.25; p = 0.26) indicating no significant association between vitamin d intake and risk of gc. we failed to find a significant association between serum vitamin d levels and risk of gc (or: 0.92; 95% ci: 0.74-1.14; p = 0.429). among men,the pooled effect size or highest versus lowest category of serum vitamin d levels was 0.92 (95% ci: 0.71,1.18,p = 0.49). the corresponding figures in women were 1.04 and 95% ci: 0.74-1.47 (p = 0.80). conclusion: we found no evidence for the significant association between vitamin d status and risk of gc. however,due to limited data in this field,further studies are required to reach a definite conclusion. © 2015 journal of research in medical sciences.