Post-COVID-19 syndrome
appears to be a multi-organ illness with a
broad spectrum of manifestations, occurring after
even mild acute illness. Limited data currently
available has suggested that vitamin D deficiency
may play a role in COVID-19 cases. However,
to our knowledge, no study has examined
the frequency of vitamin D deficiency in post-
COVID-19 cases and its effect on the symptom
severity. The aim of this study is to both screen
the frequency of vitamin D deficiency in post-
COVID-19 syndrome patients and to study its relation
to persistent symptoms.