Vitamin D status of children with Paediatric Inflammatory Multisystem Syndrome Temporally associated with Severe acute respiratory syndrome coronavirus 2 (PIMS-TS).

Coronavirus disease 2019 (COVID-19), has caused mild illness in children, until the emergence of the novel hyperinflammatory condition PIMS-TS: Paediatric Inflammatory Multisystem Syndrome Temporally associated with Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). PIMS-TS is thought to be a post- SARS-CoV-2 immune dysregulation with excessive inflammatory cytokine release. We studied 25 hydroxyvitamin D (25OHD) concentrations in children with PIMS-TS, admitted to a tertiary paediatric hospital in the United Kingdom (U.K), due to its postulated role in cytokine regulation and immune response. Eighteen children [median (range) age 8.9 (0.3 to 14.6) years, male=10] met the case definition. Majority were of Black, Asian and Minority Ethnic (BAME) origin [89%, 16/18]. Positive SARS-CoV-2 IgG antibodies were present in 94% (17/18) and RNA by PCR in 6% (1/18). 72% of the cohort were vitamin D deficient (<30nmol/L). The mean 25OHD concentration was significantly lower when compared to the population mean from the 2015/16 National Diet and Nutrition Survey (children aged 4-10 years) [24 vs 54nmol/L (95% CI: -38.6, -19.7); p<0.001]. The PICU group had lower mean 25OHD concentrations compared to the non-PICU group, but this was not statistically significant [19.5 vs 31.9 nmol/L; p=0.11]. The higher susceptibility of BAME children to PIMS-TS and also vitamin D deficiency merits contemplation. Whilst any link between vitamin D deficiency and the severity of COVID-19 and related conditions including PIMS-TS requires further evidence, public health measures to improve vitamin D status of the U.K BAME population has been long overdue.