Global, regional and national prevalence of copper, selenium and zinc deficiencies in women of childbearing age: protocol for systematic review and meta-analysis

INTRODUCTION: Micronutrient deficiencies are common in low-income and middle-income countries and are usually related to inadequate food intake, poor diet quality and low bioavailability. Copper, selenium and zinc are essential minerals in several enzymatic reactions and their deficiencies are associated with worse prognosis in pregnancy, compromising maternal health as well as her offspring. Thus, the objective of the present systematic review will be to describe the prevalence of copper, selenium and zinc deficiencies in women of childbearing age. METHODS AND ANALYSIS: The search will be performed by independent reviewers. The bases used will be PubMed/MEDLINE, Science direct, Lilacs, Adolec, Scopus, EMBASE, CINAHL, Web of Science, CENTRAL, IMSEAR, PAHOS, WPRIM, IMEMR, AIM for grey literature OpenGrey and OVID. National data will be searched in BDTD. A first search will be performed and a second search will be performed just before submission. Risk of bias assessment will be performed using the Joanna Briggs group prevalence study checklist. Combinable studies will be performed meta-analysis. Heterogeneity will be tested using Cochran’s Q test and quantified by the inconsistency test (I²). In the presence of high heterogeneity, meta-analysis will be performed using the random effects model with Stata metaprop. Summary prevalence will be generated for each outcome, presented in Forest plot figures. ETHICS AND DISSEMINATION: This systematic review will be solely based on published and retrievable literature, no ethics approval will be obtained. Our dissemination strategy will involve the presentation in scientific meetings, as well as the publication of article(s), posters and presentations in congresses. PROSPERO REGISTRATION NUMBER: CRD42020165352.