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Vitamin D levels and COVID-19 mortality


Vitamin D plays many important roles in the immune system, and some research suggests that it reduces the duration of some viral infections. The relationship between vitamin D status and COVID-19, however, is unknown.

The study

It was a retrospective cohort study of 780 lab-confirmed cases of COVID-19 in which blood levels of vitamin D had been evaluated. Medical records prior to admission were used to determine baseline vitamin D levels.

The results

People with vitamin D deficiency were significantly more likely to die from COVID-19. This was especially true for three subgroups: male patients, patients aged 50+, and patients with comorbidities.


People with lower vitamin D may be more susceptible to inflammation to begin with, and so more susceptible to COVID-19 complications. As the authors stressed, however, this was a preliminary study for early dissemination of results; data are subject to change. Also, this is a preprint paper; it hasn’t been peer-reviewed.

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