nutrition bytes by aryn doll research continues to reveal the importance of optimal vitamin d levels in covid-19 the latest research continues to highlight the importance of covid-19 patients hospitalized with mild and severe cases different groups based on the amount of respiratory distress "...vitamin d deficiency made deficiency made individuals individuals three times as likely to three times as likely to become infected with covid-19 vitamin d is known to have level should be measured in all patients..." natural grocers® 17