Brain changes in neuroimaging of adult patients with vitamin D deficiency: systematic review protocol

INTRODUCTION: Brain abnormalities detected through neuroimaging are described in patients with vitamin D deficiency, however, it is still not clear which cerebral alterations are more frequent and characteristic in this population. Thus, this review aims to identify and classify which are the main and most frequent brain changes found by neuroimaging in patients with vitamin D deficiency. METHODS AND ANALYSIS: The study protocol was constructed in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols and the leading research question was formulated through Population, Intervention, Comparator, Outcome, Setting. The evidence will be researched at the following electronic databases: PubMed, PsycINFO, Scopus, Web of Science and EMBASE. Two researchers will work in the selection, analysis and inclusion phases of the articles. In the case of divergence, a third-party reviewer will be contacted. The following studies will be included: (1) cohort studies, case–control studies and cross-sectional studies; (2) studies carried out on patients with serum 25-hydroxyvitamin D levels below 30 ng/mL; (3) studies conducted with an adult population; (4) studies using neuroimaging methods. Articles considered eligible will be analysed by the Newcastle-Ottawa Quality Assessment Scale/cross-section studies to evaluate study quality. The survey will be conducted from June to December 2022. ETHICS AND DISSEMINATION: The identification of the main and most frequent brain alterations found through neuroimaging in patients with vitamin D deficiency can guide professionals as to the identification which of the main cerebral pathologies detected through neuroimaging are related to vitamin D deficiency, in choosing more sensitive and specific neuroimaging tests to detect these brain changes, in addition to emphasising the importance of monitoring and maintaining adequate serum levels of vitamin D, in order to reduce possible cognitive sequelae. Results will be announced at national and international conferences. PROSPERO REGISTRATION NUMBER: CRD42018100074.