Serum vitamin D levels and type 2 diabetic erectile dysfunction: A protocol for systematic review and meta-analysis

INTRODUCTION: Diabetic erectile dysfunction (DED) has gradually become a worldwide problem. Due to the mechanism of DED is not clear, it is impossible to treat it pertinently. Recently, some studies have shown that vitamin D is associated with DED, type 2 diabetes mellitus (T2DM) and erectile dysfunction (ED), but there is no systematic review and meta-analysis on the relationship between vitamin D and DED. METHODS AND ANALYSIS: The databases of English databases (PubMed, MEDLINE, EMBASE, Web of Science, Cochrane Library) and Chinese databases (China National Knowledge Infrastructure, China Biology Medicine Database, Wanfang Database, VIP Database) will be retrieved. The search strategy that will be run in the PubMed and tailored to the other database when necessary is presented in Table 1 . RevMan 5.3 and Stata 11.0 will be used for Systematic Review and Meta-analysis. This protocol reported under the Preferred Reporting ltems for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement, and we will report the systematic review by following the PRISMA statement. RESULTS: Through a systematic review, and meta-analysis when necessary, we can obtain the relationship between vitamin D and DED. We will share our findings in the third quarter of 2021. CONCLUSION: The association between serum vitamin D levels and type 2 diabetic erectile dysfunction will be assessed. Besides, the results of this review may provide some help for clinicians to make decisions. ETHICS AND DISSEMINATION: Ethical approval is not required as the review is a secondary study based on published literature. The results will be published in a public issue journal to provide evidence-based medical evidence for urologists and andrologists to make better clinical decisions. PROTOCOL REGISTRATION NUMBER: INPLASY202040164.