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

Aim We aim to study the relationship between vitamin D level, risk and severity of COVID-19 infection in pediatric population through systematic review. Methods We searched PubMed, CINAHL, EMBASE, Cochrane Library and Google Scholar from December 2019 to June 2021 for retrieving articles studying association between vitamin D deficiency with COVID-19. Qualitative details were synthesized in evidence table and quantitative data was used for deriving pooled estimate through meta-analysis. Results 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. Conclusion 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.