respiratory tract infection, especially in patients with vitamin D deficiency. Whether vitamin D
is associated with coronavirus disease 2019 (COVID-19) incidence is unknown. Objective
To examine whether the last vitamin D status before COVID-19 testing is associated with
COVID-19 test results. Design, Setting, and Participants This retrospective cohort study at an
urban academic medical center included patients with a 25-hydroxycholecalciferol or 1, 25 …