Low vitamin D levels and prognosis in a COVID-19 pediatric population: a systematic review

We aim to study the relationship between vitamin D level, risk and severity of Coronavirus disease of 2019 (COVID-19) infection in pediatric population through systematic review. We searched PubMed, CINAHL, EMBASE, Cochrane Library and Google Scholar from December 2019 to June 2021 for retrieving articles studying association between vitamin D deficiencies with COVID-19. Qualitative details were synthesized in evidence table and quantitative data was used for deriving pooled estimate through meta-analysis. After initial search of 2261 articles, eight eligible studies (two reviews) were included in the systematic review. Meta-analysis of the quantitative data (six studies) showed pooled prevalence of vitamin D deficiency as 45.91% (95% CI: 25.148-67.450). In infected pediatric patients, low levels of vitamin D increased the risk of severe disease (odds ratio-5.5; 95% CI: 1.560-19.515; P = 0.008). It was also found that children and adolescents having vitamin D deficiency had greater risk of COVID infection as compared to patients with normal vitamin D levels. Improvement in disease severity with vitamin D supplementation was also noted. The systematic review showed that almost half of the pediatric COVID patients suffer from vitamin D deficiency. It is also clear that the low level of vitamin D is associated with greater risk of infection and poorer outcome in pediatrics.