Table 1.
Search strategy adopted in the present systematic review and meta-analysis.
| Search Strategy | Details | |
|---|---|---|
| Search string | (“COVID-19” OR “SARS-CoV-2” OR “coronavirus” OR “2019-nCoV”) AND (“vitamin D” OR “cholecalciferol” OR “calcitriol”) | |
| Inclusion criteria | P (patients/population): | Patients with COVID-19 diagnosis |
| I (intervention/exposure): | Patients with COVID-19 infection supplemented with Vitamin D | |
| C (comparisons/comparators): | Patients diagnosed with COVID-19 who received standard therapy, lower dose, no therapy or placebo | |
| O (outcome): | Mortality, ICU admission, intubation, and hospital length of stay | |
| S (study design) | RCT, cohort, and quasi-experimental studies were considered | |
| Databases | PubMed/MEDLINE, Scopus, Cochrane, and Google Scholar | |
| Exclusion criteria | Items not directly pertinent to the query string; studies did not have sufficient information and data available to be analyzed; articles not meeting the PICOS criteria | |
| Time filter | None (from inception) | |
| Language filter | None (any language) | |