Object:To explore the correlation between serum vitamin D level and the occurrence and pathological grade of gastric cancer.Data sources:Search the PubMed, Embase, Web of Science, Cochrane,Chinese Journal Full-text Database (CNKI), Wanfang Science and Technology Journal Full-text Database, Chinese Science and Technology Journal Full-text Database (VIP), Chinese Biomedical Literature Database (CBM), All articles about the correlation between serum vitamin D levels and gastric cancer published before July 2021.Results:10 trials with 1159 cases of gastric cancer patients and 33387 cases of normal control patients were analyzed. The serum vitamin D level of the gastric cancer group(15.56±7.46ng/ml) was lower than the control group (17.60±1.61ng/ml), and the difference was statistically significant (MD=-8.28, 95%CI: -14.32~-2.23, P Conclusions:Vitamin D levels are negatively correlated with the occurrence of gastric cancer. Vitamin D levels are significantly correlated with different clinical stages, degrees of differentiation and lymph node metastasis, suggesting that low vitamin D levels may be a predictor of poor prognosis in gastric cancer.