Vitamin D And Coronavirus: What Does The Science Say?

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Since the pandemic, scientists are in a race to develop effective treatments to lower the risks of getting severally sick from COVID-19. 

Vitamin D And Coronavirus 

Many voices claim a strong link between vitamin D and the prevention of infections and inflammatory conditions. For instance, data analyzed by researchers from the University of Chicago Medicine suggest a potential of vitamin D to slow down the spread of coronavirus. The findings argue for a significant link between vitamin D deficiency and the risk of coronavirus infection [1]. 

But what makes vitamin D that relevant to COVID-19? How does it work to reduce your infections chances and the severity of getting sick from the coronavirus?  

Read more to learn about the correlation between vitamin D and coronavirus.  

What Is Vitamin D? 

Vitamin D is an essential lipid-soluble vitamin.  

People can naturally get vitamin D through exposure to sunlight from late March till September. In the lack of enough sunlight, vitamin D could be still found in food and supplements.   

Both vitamin D2 and vitamin D3 are recognized as prohormones that play an essential role in increasing immunity.  

The two main forms of vitamin D are vitamin D3 and vitamin D2; both exhibit similar response in the body. Nevertheless, some animal studies showed that vitamin D3 could be more toxic than vitamin D2.  

While vitamin D3 is either synthesized in the skin when exposed to UVB radiation or ingested in food, vitamin D2 is mostly chemically developed or found in fortified food [2]. 

Vitamin D Function In Our Body 

Vitamin D's primary function is to regulate the absorption and distribution of calcium and phosphates in the body, ensuring the sufficient supply of these nutrients needed for bones, teeth, and muscles health [3]. 

Sources Of Vitamin D 

People can cover their vitamin D needs from a combination of food, supplements, and sun exposure. 


Few food sources contain abundant amounts of vitamin D. Mushrooms, and the flesh of fatty fish such as trout, salmon, and tuna are the richest in vitamin D micrograms per serving.  

Vitamin D is also found in beef liver, cheese, and egg yolks but with relatively lower amounts [4].  

The FDA has approved UV-treated food powders as a food additive rich in vitamin D.  

Dietary Supplements 

While it could be difficult for some people to get vitamin D from food, especially those following a strict vegan diet, many producers offer dietary supplements with sufficient amounts of vitamin D2 and vitamin D3.  

Vitamin D2 is produced by applying UV irradiation to ergosterol in yeast, while lanolin irradiation or cholesterol conversion are used to produce vitamin D3.  

Sun Exposure 

The UVB radiation from the sun penetrate the human skin and covert a chemical compound to a previtamin D3, which is then converted to vitamin D3 [4].  

Many factors might affect vitamin D synthesis; season, time of day, clouds, smog, skin color, and applied sunscreen influence vitamin D generation in your body. That is why the elderly and people with dark skin and lower sun exposure are more likely to have vitamin D deficiency and develop a greater risk of infection.   

What Is The Correlation Between Vitamin D And COVID-19? 

Observational data showed that mortality rates increase in Northern countries. These data suggest a strong link between UV light exposure, indirect vitamin D secretion, and the risk of severe sickness from COVID-19. Nevertheless, these studies indicated that UV light also affects immunity independent of vitamin D [5].  

Former studies have suggested vitamin D deficiency as a primary factor in ARIs (acute respiratory infections). Vitamin D also reduces inflammatory responses and enhances the defense mechanism against respiratory infection. 

Other studies have also linked childhood respiratory illness and the deficiency of vitamin D [6]. 

The research explained that vitamin D induced protection against COVID-19 comes from the increased the ratio of ACE2 to ACE.  

ACE2 is an enzyme attached to the membranes of cells located in the lungs, arteries, heart, kidney, and intestines. This enzyme lowers blood pressure. ACE is a converting enzyme that controls blood pressure by regulating the volume of fluids in the body. 

A study from July 2020 has investigated the impact of combining AT1R antagonists and vitamin D in treating severe acute respiratory distress syndrome caused by coronavirus infection. The study showed that vitamin D inhibits the increase in renin levels caused by the antagonists and offers protection for lung injury induced by COVID-19 [7].  

Dangers Of Vitamin D Toxicity

The risk of intoxication from vitamin D is rare; people who undergo heavy doses of treatments have serious dangers of intoxication.  

Toxicity of vitamin D cause hypercalcemia (abnormal levels of calcium in the blood) and disorder in bone metabolism regulation. 

It leads to other symptoms like confusion, apathy, agitation, irritability, severe cases, stupor, and coma [8]. 

There are other severe symptoms of vitamin D toxicity that are not usually apparent. Symptoms such as fatigue, bone pain, anorexia, stomach pain and change in the mental status should be taken seriously and reported to the personal doctor. 

Recommended Doses Of Vitamin D  

Considering that the advantageous effect of vitamin D takes months to develop, the optimal dose recommended is 1000-2000 IU per day [5].  

(1 microgram of vitamin D equals 40 IU) 

Breastfeeding and pregnant women need ten micrograms of vitamin D per day. 

getting sunshine for Vitamin D and Coronavirus immunity

The Department of Health and Social Care recommends that newborns have a daily supplement containing 8.5 to 10 micrograms of vitamin D during their first year [3]. 

Summing Up  

Evidence shows a remarkable overlap between vitamin D deficiency and other factors such as male sex, obesity, older age, ethnicity, hypertension, diabetes affecting severe sickness and death from COVID-19. 

It is not simple to understand the real impact of vitamin D on immunity to translate it to clinical practice. Nevertheless, vitamin D is a safe vitamin with no adverse effects on healthy people. 

Observational and clinical studies confirmed a significant correlation between vitamin D deficiency and severe sickness from the coronavirus. Research surrounding vitamin D association with COVID-19 grows every day; new collected evidence may confirm or reject the hypothesis of infection protection induced by vitamin D intakes. Until then, taking safe doses of vitamin D can be considered a safe strategy to increasing your chances of pandemic survival.  



Al Feky