Objective: In this study, we aimed to determine the prevalence and clinical importance of vitamin D deficiency in children and adolescent patients who were hospitalized with the diagnosis of COVID-19. Material and Methods: 40 patients who were diagnosed to have COVID-19 and hospitalized with the real-time reverse transcription polymerase chain reaction (RT-PCR) method were included. The control group consisted of 45 healthy patients with normal vitamin D levels. The age of admission, clinical and laboratory data, and 25-hydroxycholecalciferol (25-OHD) and parathormone (PTH) levels were recorded. Those with vitamin D levels which are below 20 ng/ml were determined as Group 1 and those with ≥20 ng/ml as Group 2. Results: The median levels of vitamin D level were 13.14 (4.19-69.28) in the group of patients with COVID-19 and 34.81(3.8-77.42) in the control group. Compared to the control group, there was a statistically significantly lower vitamin D level (p <0.001) in the COVID-19 patient group. At admission, the symptom of fever was significantly higher in Group 1 than in Group 2 (p =0.038). The distribution of disease severity according to vitamin D levels was not found significantly different. In conclusion; our study is the first to evaluate vitamin D levels and its relationship with clinical findings in pediatric patients diagnosed with COVID-19. There are significantly lower levels of vitamin D in children with COVID-19 than those in the control group. This shows that vitamin D, which is effective in the immunological mechanism, also has an effect in the physiopathology of the disease.

Background: The novel coronavirus disease (Covid-19) can progress with mild to moderate or self-limiting clinical findings in children. The aim of this study was to investigate the disease features of Covid-19 in Turkish children. Methods: Children diagnosed by the method of RT-PCR for Covid-19 at the Dicle University Department of Pediatric, between April and June 2020, were evaluated. Hospital records were investigated retrospectively. Results: One hundred and five patients children with the mean age of 108.64±65.61 were enrolled in this study. The most common cause of transmission in pediatric patients was contacting with a family member diagnosed with COVID-19 (n=91, 86.7%).The most common admission complaints were dry cough (n=17, 16.2%), fever (n=16, 15.2%), lassitude and fatigue (n=14, 13.3%) respectively. More than 95 % of all children with Covid-19 had asymptomatic, mild, or moderate cases. CRP was identified only independent factor associated with long duration of hospitalization. Conclusion: The results of this study show preliminary results of a study investigating the effect of Covid-19 on Turkish children. A clear understanding of the local epidemiology of corona virus infections and identification of risk factors is critical for the successful implementation of the prevention and control program.