You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

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.
["Diagnosis", "Treatment"]