Inclusion Criteria:  males and females aged 18 to 65 years who did not take Vitamin D supplementation healthcare workers, during the pandemic who had not previously tolerated new coronavirus infection  Exclusion Criteria:  pregnancy or nursing a history of granulomatous diseases severe gastrointestinal diseases (clinically apparent malabsorption syndrome) liver disease kidney disease individual intolerance drug vitamin D supplementation drugs known to affect vitamin D metabolism (e.g., anticonvulsants, glucocorticoids, diuretics)