Kanhatai ChiengthongWisit CheungpasitpornCharat ThongprayoonPloypin LertjitbanjongLiam D. CatoTarun BathiniPatompong UngprasertMichael A. MaoRonpichai ChokesuwattanaskulUniversity Hospital Birmingham NHS Foundation TrustKing Chulalongkorn Memorial Hospital, Faculty of Medicine Chulalongkorn UniversityFaculty of Medicine, Siriraj Hospital, Mahidol UniversityThe University of ArizonaMayo ClinicUniversity of Mississippi Medical CenterThe Mary Imogene Bassett HospitalMayo Clinic in Jacksonville, Florida2020-06-022020-06-022020-01-01Journal of Evidence-Based Medicine. (2020)17565391175653832-s2.0-85085123452https://repository.li.mahidol.ac.th/handle/20.500.14594/56331© 2020 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd Objective: Vitamin D status plays an important role in immunoregulation, and a deficiency is believed to be related to Graft Versus Host Disease (GVHD) in patients after hematopoietic stem cell transplantation (HSCT). We aim to study the association between vitamin D deficiency and GVHD after HSCT. Methods: A literature search was conducted utilizing MEDLINE, EMBASE, and The Cochrane Library Database from inception to July 2019. Eligible studies were required to1 be clinical trials or observational studies (cohort, case-control, or cross-sectional studies);2 provide data to calculate the odds ratios (OR) of GVHD in HSCT patients with vitamin D deficiency. Two reviewers independently extracted the data and assessed the risk of bias. Pooled odds ratios (OR) with 95% confidence interval (CI) were estimated using random-effects meta-analysis through the Comprehensive Meta-Analysis 3.3 software. Results: In total, 8 observational studies consisting of 1335 HSCT patients were enrolled in this systematic review. Overall, there was no significant association between vitamin D deficiency and acute GVHD (OR = 1.06, 95% CI 0.74-1.53, P > 0.05). There was no significant association between vitamin D deficiency and chronic GVHD (OR = 1.75, 95% CI 0.72-4.26, P > 0.05). Funnel plots and Egger regression asymmetry test were performed and showed no publication bias. Conclusion: There is not a statistically significant association between vitamin D deficiency and neither acute nor chronic GVHD.Mahidol UniversityMedicineArticleSCOPUS10.1111/jebm.12383