inclusion criteria: patients admitted to icu with severe covid-19 disease and in need for invasive or non-invasive respiratory support with low levels of vitamin d (<50 nmol/l) measured on admission. all patients are older than 18 years and have confirmed covid-19 disease with pcr test.

inclusion criteria: patients admitted to icu with severe covid-19 disease and in need for invasive or non-invasive respiratory support with low levels of vitamin d (<50 nmol/l) measured on admission. all patients are older than 18 years and have confirmed covid-19 disease with pcr test.