Plasma 25-hydroxyvitamin D deficiency in the peri-operative period is associated with survival outcome in colorectal cancer patients: a meta-analysis

Surgery had a significant impact on 25-hydroxyvitamin D (25-(OH)D) levels. Uncertainty still existed regarding the effects of peri-operative 25(OH)D deficiency on colorectal cancer (CRC) patients’ prognosis. The purpose of the present study was to explore the potential association between the peri-operative 25(OH)D deficiency and the survival outcome of CRC. Seven electronic databases [including PubMed, EMBASE, Web of Science, The Cochrane Library, OvidMEDLINE(R), China National Knowledge Infrastructure (CNKI) and Wangfang data] were searched without language limitations. The primary outcomes were overall survival and all-cause mortality. Secondary outcomes were the incidence of 25(OH)D deficiency and risk variables for low 25(OH)D level in the peri-operative period. 14 eligible studies were obtained with 9324 patients for meta-analysis. In the peri-operative period, the pooled incidence of blood 25(OH)D deficiency was 59.61