Abstract
There is still limited evidence regarding the influence of vitamin D in people with COVID-19. In this systematic review and meta-analysis, we analyze the association between vitamin D deficiency and COVID-19 severity, via an analysis of the prevalence of vitamin D deficiency and insufficiency in people with the disease. Five online databases—Embase, PubMed, Scopus, Web of Science, ScienceDirect and pre-print Medrevix were searched. The inclusion criteria were observational studies measuring serum vitamin D in adult and elderly subjects with COVID-19. The main outcome was the prevalence of vitamin D deficiency in severe cases of COVID-19. We carried out a meta-analysis with random effect measures. We identified 1542 articles and selected 27. Vitamin D deficiency was not associated with a higher chance of infection by COVID-19 (OR = 1.35; 95% CI = 0.80–1.88), but we identified that severe cases of COVID-19 present 64% (OR = 1.64; 95% CI = 1.30–2.09) more vitamin D deficiency compared with mild cases. A vitamin D concentration insufficiency increased hospitalization (OR = 1.81, 95% CI = 1.41–2.21) and mortality from COVID-19 (OR = 1.82, 95% CI = 1.06–2.58). We observed a positive association between vitamin D deficiency and the severity of the disease.
Authors’ contributions
A.D.D. and L.M.G.A. coleted the data and drafted the manuscript. J.M.S. and T.A.O. revised the manuscript. M.P. contributed to the conception of the work, drafted, revised the manuscript and supervised the study process. The authors approved the final version of the manuscript for publication.