Several studies, generally small and poorly controlled have suggested that patients with low levels of vitamin D have excess risk for infection with SARS-CoV-2. This prospective cohort study involved 18,000 participants whose vitamin D levels were assessed both a few months prior to the COVID-19 pandemic and in the middle of the pandemic (August–November 2020). SARS-CoV-2 seropositivity was assessed through November 2020; clinical illness was not assessed.
Nine hundred participants (5%) became SARS-CoV-2–positive during the study. On univariate analysis, positivity was associated with low vitamin D levels and with various sociodemographic parametres. However, on multivariate analysis and with other methods of adjustment, seropositivity was not associated with 25-hydroxyvitamin D levels of
20 ng/mL or 30 ng/mL.
These results add to the now generally accepted belief that vitamin D levels are not associated with risk for SARS-CoV-2 infection. This fact, of course, renders moot any discussion of whether supplementation would lower risk.