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This is a summary of "Vitamin D Insufficiency is Prevalent in Severe COVID-19"


Does Vitamin D protect against COVID-19?

Despite being heavily shared on social media, this study does not demonstrate a relationship between Vitamin D deficiency and the severity of COVID infection.

Key takeaways

Why is this important?

Vitamin D supplementation is relatively cheap and safe. If low vitamin D levels were related to COVID-19 disease severity, then supplementing with Vitamin D pills would be an easy fix.

They chose to study the relationship between Vitamin D and COVID-19 severity because there is evidence in animals and in cells that Vitamin D is important for regulating the immune system in the lungs. There is some evidence that people with low Vitamin D levels get more lung infections in general. But, having higher Vitamin D levels might just be a marker for overall healthiness, eating better, getting more sunlight, or many other confounding factors unrelated to lung health. From the data, it’s not clear if we should be giving people Vitamin D supplements to protect their lungs. There is some evidence that giving vitamin D prior to some types of surgery 1 or to people with low vitamin D levels can protect the lungs 2; there is also a large study showing that giving a large dose of vitamin D to critically ill people does not improve their chance of survival 3.

What did the study do?

How was it reported?

The original paper is a preprint study. It has not been certified by peer review from other researchers, and information presented may be erroneous. Do not use it to guide clinical practice! Learn more →

Original Paper DOI10.1101/2020.04.24.20075838

Vitamin D Insufficiency is Prevalent in Severe COVID-19 [PDF]

Additional Reading

For more details and technical discussion of the study, we recommend reading the following resources:


  1. Vitamin D deficiency contributes directly to the acute respiratory distress syndrome (ARDS)
  2. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
  3. Early High-Dose Vitamin D3 for Critically Ill, Vitamin D–Deficient Patients
  4. COVID-19 outbreak at a large homeless shelter in Boston: Implications for universal testing
  5. Serum Vitamin D Concentrations Among Elderly People in Europe

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