Vitamin D Status in a Large, Ethnically Diverse Patient Population Living in South East London at the Onset of the COVID-19 Pandemic: A Cross-Sectional Study Including a SARS-CoV-2 Positive Patient Subset

在新冠疫情爆发初期，居住在伦敦东南部的大型、种族多元化患者群体中维生素D状况：一项包含SARS-CoV-2阳性患者亚组的横断面研究