COVID-19(5) Result(5) 95% CI(4) country(3) Evidence(3) participant(3) individual(3) association(3) confounders(3) USA(3) recommendation(2) Support(2) greater(2) severity(2) SARS-COV-2 infection(2) HCWs(2) risk(2) information(2) less(2) nutritional treatment(2) healthcare worker(2) France(2) Protective(2) investigated(2) Italy(2) supported(2) COVID-19 case(2) provided(2) Germany(2) COVID-19 severity(2)