COVID-19 and Vitamin D

People tend to look for a completely new, sometimes unrealistic, cure for the diseases that cause fear. This is so natural. 

COVID-19 is one of those diseases. There were vaccines developed, drugs trialed, old drugs dug up in order to find an absolute cure. So, far, there is still not a single drug or vaccine there that could be called a single factor cure for COVID-19.

Vitamin D was one of the drugs, or rather, supplements that were attributed a magic power of defeating the COVID-19 pandemic. Is it true though?

There is no question that Vitamin D is an amazing biologically active substance that makes our bones strong, helps losing weight, prevents some cancers, battles depression and anxiety. But, does Vitamin D cure COVID-19?

Firstly, it is too early to say. The whole of the COVID-19 pandemic is just two years old. However, there are some studies that offered rather promising results about the role of Vitamin D in the management of COVID-19.


New research.

New research from Trinity College Dublin and the University of Edinburgh has examined the association between vitamin D and COVID-19 and found that ambient ultraviolet B (UVB) radiation (which is key for vitamin D production in the skin) at an individual’s place of residence in the weeks before COVID-19 infection, was strongly protective against severe disease and death. The paper was published in the journal Scientific Reports on September 14, 2021.

Previous studies have linked vitamin D deficiency with increased susceptibility to viral and bacterial respiratory infections. Similarly, several observational studies found a strong correlation between vitamin D deficiency and COVID-19, but it could be that these effects are confounded and in fact a result of other factors, such as obesity, older age, or chronic illness which are also linked with low vitamin D.

Vitamin D can also support the immune system through a number of immune pathways involved in fighting SARS-CoV-2. Many recent studies confirm the pivotal role of vitamin D in viral infections.

This study shows that, counter-intuitively, countries at a lower latitude and typically sunny countries, such as Spain and Northern Italy, had low concentrations of vitamin D and high rates of vitamin D deficiency. These countries also experienced the highest infection and death rates in Europe.

The northern latitude countries of Norway, Finland, and Sweden, have higher vitamin D levels despite less UVB sunlight exposure because supplementation and fortification of foods are more common. These Nordic countries have lower COVID-19 infection and death rates. The correlation between low vitamin D levels and death from COVID-19 is statistically significant.

There are studies that resulted in the lack of any evidence of the correlation between Vitamin D and severity and susceptibility to COVID-19.


The take-home message is that it is better to err on a side of caution and do what is universally good for health. No matter what the next scientific study says about Vitamin D being a cure for COVID-19, there is no doubt, maintaining good levels of Vitamin D is universally beneficial. The journey to good levels of Vitamin D starts with testing. 


“An observational and Mendelian randomisation study on vitamin D and COVID-19 risk in UK Biobank” by Xue Li, Jos van Geffen, Michiel van Weele, Xiaomeng Zhang, Yazhou He, Xiangrui Meng, Maria Timofeeva, Harry Campbell, Malcolm Dunlop, Lina Zgaga and Evropi Theodoratou, 14 September 2021, Scientific Reports.

“Vitamin D and Inflammation: Potential Implications for Severity of Covid-19” by E. Laird, J. Rhodes and R.A. Kenny, 11 May 2020, Irish Medical Journal.

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