Calcitriol Supplementation in COVID-19 Patients

Inclusion Criteria: 1. Hospitalized symptomatic COVID-19 patients; 2. COVID-19 nucleic acid Ct value \< 28 (both orf1ab gene Ct value and N gene Ct value \< 28); 3. Vitamin D deficiency: 25OHD ≤ 20ng/ml; 4. Age: 18-70 years old; Exclusion Criteria: 1. Asymptomatic COVID-19 patients ； 2. Hypercalcemia; 3. History of primary hyperparathyroidism; 4. History of triple hyperparathyroidism; 5. Patients who are allergic to calcitriol; 6. Pregnant or lactating women; 7. Patients with severe heart or lung diseases or tumor history; 8. Patients already taking vitamin D or its similar preparations; 9. Participants in other interventional clinical studies (including taking paxlovid); 10. Patients with renal insufficiency (eGFR\<60ml/min/1.73m2); 11. Patients considered unsuitable for this study by the investigator；