Inflammation is a necessary response by the immune system to infections or injuries, but if this inflammatory response doesn’t stop in time, it can cause severe damage to cells and tissues.
Hyper-inflammation resulting in cytokine storm syndrome (CSS) and acute respiratory distress syndrome (ARDS) are often seen in severe COVID cases.
Inflammation and fibrosis in COVID patients with milder symptoms can damage tissue function and lead to lung disease.
Therefore, scientists are looking for therapies or drugs to help suppresses the immune system and overcome inflammation.
Vitamin D appears to have the ability to lower inflammation caused by T cells in the lungs of COVID patients.
To minimise harm and increase the benefit of taking this vitamin, scientists want to find out how and why and at what dosage the inflammation will be decreased.
For these reasons, Dr Kazemian and colleagues examined first how viruses affect lung cells.
They noticed that in COVID patients, the immune cells in the lung go into overdrive causing too much inflammation.
Then, they found that viruses activate a biochemical pathway which is part of the immune system called the complement system.
The team looked at different methods for blocking the activation of that pathway and reducing inflammation.
Dr Kazemian, study co-author, said:
“In normal infections, Th1 cells, a subset of T cells, go through a pro-inflammatory phase.
The pro-inflammatory phase clears the infection, and then the system shuts down and goes to anti-inflammatory phase.
Vitamin D helps to speed up this transition from pro-inflammatory to the anti-inflammatory phase of the T cells.
We don’t know definitively, but theorize the vitamin could potentially help patients with severe inflammation caused by Th1 cells.”
The cell’s response to vitamin D was unusual, suggesting vitamin D deficiency in these patients as a possible reason why the pro-inflammatory phase won’t shut down.
They suggest that besides existing treatments, a prescription of a highly concentrated form of vitamin D can help COVID patients to recover quickly from the disease.
Dr Kazemian said:
“We found that vitamin D—a specialized form of it, not the form you can get at the drugstore—has the potential to reduce inflammation in the test tube, and we figured out how and why it does that.
However, it’s important to understand that we did not carry out a clinical study, and the results of our experiments in the test tube need to be tested in clinical trials in actual patients.”
They don’t recommend vitamin D supplementation sold over the counter.
“We do not recommend the use of normal vitamin D off the shelf at the pharmacy.
No one should be taking more than the recommended doses of vitamin D in an attempt to prevent or combat COVID infections.”
The study was published in the journal Nature Immunology (Chauss et al., 2021).