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;

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;

inclusion criteria: hospitalized symptomatic covid-19 patients; covid-19 nucleic acid ct value < 28 (both orf1ab gene ct value and n gene ct value < 28); vitamin d deficiency: 25ohd ≤ 20ng/ml; age: 18-70 years old;

inclusion criteria: hospitalized symptomatic covid-19 patients; covid-19 nucleic acid ct value < 28 (both orf1ab gene ct value and n gene ct value < 28); vitamin d deficiency: 25ohd ≤ 20ng/ml; age: 18-70 years old;