American scientists have found out that patients with COVID-19 with normal blood levels of vitamin D have a significantly lower number of serious cases and deaths than those who have its deficit. The results of the study have been published in the journal PLOS ONE.
Scientists at Boston University School of Medicine have analyzed how vitamin D levels in the blood affect disease severity and mortality rates in COVID-19 patients.
The researchers took blood samples from 235 patients at the time of their admission to the hospital and measured 25-hydroxyvitamin D in serum, a vitamin D level marker.
These patients were later observed recording the clinical severity of infection and outcome, as well as severe symptoms such as loss of consciousness, difficulty breathing, and hypoxia. They also had an inflammatory marker in their blood – C-reactive protein and the number of lymphocytes – immune cells that help fight infection.
The researchers then compared all these parameters in patients with vitamin D deficiency and patients with a sufficient level – at least 30 nanograms per milliliter.
It turned out that in patients with COVID-19, who have enough vitamin D, the risk of adverse clinical outcomes – the development of severe complications or death – is much lower.
In particular, the authors believed that patients over 40 years of age with sufficient vitamin D levels were 51.5 percent less likely to die from infection than patients with vitamin D deficiency. In addition, they have lower levels of C-reactive protein and higher levels of lymphocytes.
“This study provides direct evidence that vitamin D deficiency can prevent complications, including a cytokine storm, and ultimately death from COVID-19,” said Boston University School of Medicine Professor of Physiology, Biophysics, and Molecular Medicine, Dr. Michael Holick, in a press release.
In a previous study, Holick found that a sufficient amount of vitamin D in the blood reduces the risk of coronavirus infection by 54 percent and that vitamin D helps fight not only the coronavirus but also other viruses that cause upper respiratory diseases, including seasonal influenza.
According to Holyke, there is a great fear that the combination of influenza and coronavirus can significantly increase hospital admissions, complicate disease progression, and increase mortality. It is therefore wise to take vitamin D supplements to reduce the risk of infection and complications from COVID-19 and influenza, especially in the winter months when a lack of sunlight creates a shortage of this substance in the body.