Vitamin D is a fat-soluble vitamin that is different from other vitamins because the human body can absorb most of this vitamin when exposed to sunlight. It acts as a pro-hormone, which affects the hormone balance and immune regulation of the body.
The fat-soluble vitamin plays a major role in calcium absorption into the bones and a deficiency of this vitamin can result in softening of the bones called osteomalacia or a bone abnormality called rickets .
In this article, we will be exploring the possible relationship between vitamin D and COVID-19, a topic that has been in discussion since the advent of coronavirus infections.
The coronavirus attacks your respiratory system and people with low immunity levels are increasingly prone to contracting the disease . After examining several studies that have explored the role of vitamin D in preventing or managing the coronavirus infection, the following are the crucial points:
- Patients with severe coronavirus infection and symptoms had a higher level of a vitamin D deficiency than the ones who had mild symptoms .
- Individuals with a vitamin deficiency had a higher risk of developing severe illness among those who had sufficient vitamin D levels .
- Use of vitamin D supplements showed a significant reduction in respiratory tract infections caused by the coronavirus .
- Vitamin D has been shown to protect against acute respiratory infections, and older adults are the group who are most deficient in vitamin D and hence the ones most seriously affected by COVID-19.
- A correlation between vitamin D levels and cytokine storm (a hyperinflammatory condition caused by an overactive immune system) was reported, which further links vitamin D deficiency and mortality .
- A statistical analysis of data from hospitals across China, France, Germany, Italy, Iran, South Korea, Spain, Switzerland, the UK and the US showed that patients from countries with high COVID-19 mortality rates, such as Italy, Spain and the UK, had lower levels of vitamin D compared to patients in other countries .
Apart from the points discussed in the previous section of the article, one that has more data support is the link between cytokine storm and vitamin D deficiency. Cytokines are small proteins released by many different cells in the body, where they coordinate the body’s response against infection and trigger inflammation. The link between cytokine storm and coronavirus infection is that a cytokine storm can occur when, for example, the coronavirus enters the lungs, triggering an immune response, attracting immune cells to the region to attack the virus. This results in localised inflammation and in some patients, hyper inflammation which can cause serious complications, and even death . Cytokine storms are a common complication not only of covid-19 and flu but of other respiratory diseases caused by coronaviruses such as SARS and MERS, and non-infectious diseases such as multiple sclerosis and pancreatitis, explaining why some people have a severe reaction to coronaviruses while others only experience mild symptoms .
In addition to that, it also explains why young people are less affected because their immune systems are less developed, thereby only produce lower levels of inflammation-driving cytokines . So coming back to vitamin D and cytokine storm, the researcher says, “cytokine storm can severely damage lungs and lead to acute respiratory distress syndrome and death in patients. This is what seems to kill a majority of COVID-19 patients, not the destruction of the lungs by the virus itself. It is the complications from the misdirected fire from the immune system” . Not only does vitamin D enhance our innate immune systems, but also prevents our immune systems from becoming dangerously overactive, thereby pointing out that having healthy levels of vitamin D could protect patients against severe complications, including death, from COVID-19