The association between vitamin D status and COVID-19 in England: A cohort study using UK Biobank.

BACKGROUND: Recent studies indicate that vitamin D supplementation may decrease respiratory tract infections, but the association between vitamin D and COVID-19 is still unclear. OBJECTIVE: To explore the association between vitamin D status and infections, hospitalisation, and mortality due to COVID-19. METHODS: We used UK Biobank, a nationwide cohort of 500,000 individuals aged between 40 and 69 years at recruitment between 2006 and 2010. We included people with at least one serum vitamin D test, living in England with linked primary care and inpatient records. The primary exposure was serum vitamin D status measured at recruitment, defined as deficiency at