Defining vitamin D deficiency in patients with sickle cell disease; A meta-analysis

Introduction: Sickle cell disease (SCD) is one of the hereditary blood disorders that affects the red blood cells. Several lines of evidence indicated that the vitamin D deficiency (VDD) is quite common in children with SCD and vitamin D supplementation enhanced health-related quality of life in these patients. The present study is aimed to assess the exact prevalence of VDD in SCD patients using meta-analysis. Materials and Methods: A systematic search was conducted in PubMed and Google Scholar to extract the papers that contain prevalence data and numbers of patients with VDD in SCD patients and healthy people. Pooled prevalence was estimated using MAJOR module of Jamovi library. The overall risk ratio of having VDD in patients with SCD was calculated using the Review Manager (RevMan 5.4.1) program. Results: A total of 26 prevalence estimates from 25 papers were included in the meta-analysis. The pooled prevalence of VDD among SCD patients is 60% (95% CIs: 50%-70%). Further, VDD is not significantly different in both SCD patients and healthy controls (risk ratio of 1.28 and 95% CI of 0.81-2.04). Conclusion: Results of this meta-analysis indicate prevalence of VDD in SCD patients. Further, a well-designed, placebo-controlled RCTs have to be conducted to determine the effects and the safety of vitamin D supplementation in children and adults with SCD.