Can vitamin D help in treating one of the most severe forms of COVID-19? Original paper

Vitamin D plays an important role in the immune system by regulating inflammation and anti-microbial response. Immune cells such as macrophages, dendritic cells, and T cells express high levels of the vitamin D receptor, underscoring the importance of vitamin D in immune function and inflammation. In COVID-19 patients, the macrophage immune response is related to the severity of the disease.

One of the deadliest effects of COVID-19 on the body is acute respiratory distress syndrome (ARDS), which occurs due to an overactive inflammatory response in lung macrophages. When patients develop COVID-19, macrophages initiate a cytokine storm — a rapid and severe inflammatory response that floods the lungs with other immune cells and inflammatory proteins.

Studies have identified vitamin D as a potential regulator of the immune response to infection by SARS-CoV-2 (the coronavirus that causes COVID-19). The evidence suggests use of vitamin D as a COVID-19 treatment, in addition to antiviral therapies. This study asked how vitamin D supplementation may be able to limit the inflammatory response in patients with SARS-CoV-2 infection.

This narrative review investigated how vitamin D supplementation may affect the inflammatory response of macrophages (and other immune regulatory cells) and thus decrease the incidence of ARDS in patients with COVID-19.

Data from COVID-19 patients across several different countries indicated that vitamin D deficiency is correlated with levels of high C-reactive protein, a marker for inflammation and an indicator of cytokine storm. Vitamin D can suppress inflammatory cytokine production while boosting immunity.

In summary, the authors conclude that there is strong evidence that vitamin D supplementation may benefit patients with COVID-19 by reducing the macrophage-driven hyperinflammatory response in the lungs.