Ever wondered about the correlation between Vitamin D, your immunity and Covid-19? This article addresses the question of Vitamin D for Covid-19: whether the vitamin offers protection or cure to the infection.
What's On This Page
What is Vitamin D?
Vitamin D is a group of fat-soluble vitamins most popularly known for their crucial effect on the development of healthy bones.
How Do We Get It?
We know of several sources for Vitamin D.
In humans, Vitamin D is created by the action of sun rays on a form of cholesterol found in the skin.
So, these ultraviolet beta (UVB) rays lead to the creation of Vitamin D in the skin that is further activated in the Liver and Kidneys.
Other sources are from the foods we eat some of which are rich Vit D sources like
- Fatty fish like tuna, mackerel, and salmon, fish (cod) liver oils
- Foods fortified with vitamin D, like some dairy products, orange juice, soy milk, and cereals
- Beef liver, Cheese, Egg yolks,
- And lastly – from Dietary Supplements.
What Do We Know So Far About Vitamin D and Immunity?
Firstly, in addition to the effect on bones, a significant impact of Vitamin D is also the suppression of inflammatory processes
To clarify, inflammation is a key feature of what is happening in your body when the immune system is fighting illness.
Some previous studies report independent associations between low blood levels of Vitamin D and increased risk of acute respiratory tract infections.
However, there is some controversy on whether Vit D can actually protect against these respiratory infections like Influenza; with more studies pending to make any conclusions.
Studies show Vitamin D interacts with the immune system in many ways including a link between low levels and autoimmune disease.
Examples of these conditions are Multiple Sclerosis, Rheumatoid Arthritis, Type 1 Diabetes Mellitus, SLE (Systemic Lupus Erythematosus) etc.
What Does Vitamin D Do for The Immune System?
We think there might be a few different interactions, but let’s just look at one of the possibilities.
Very interesting is the way it works on specific cells of the innate immune system (the body's first responder).
These cells are called macrophages, and part of their activity is to release inflammatory cytokines in response to threats like Covid-19.
You’ve probably heard of the Cytokine storm.
It is an excessive release of these inflammatory chemicals by the immune system in response to a threat that could overwhelm the body rather than fight off the disease.
It has been shown that the entire illness process of Covid-19 is caused by a combination of the virus virulence and pro-inflammatory cytokines.
One of Vit D's activities is preventing the macrophage from releasing too many of these inflammatory cytokines.
Therefore, Vit D may provide protection from severe Covid-19 disease.
Scientists feel there are a few ways this can be demonstrated:
- They are the link to Obesity, Respiratory Infections and Elderly population.
Obesity and Covid-19
People with obesity develop a significantly more severe disease when they contract the Covid-19 infection.
They also appear to have low blood Vit D levels.
Some scientists debating the reason for the relationship between obese people and Covid-19 tend to lean towards the thinking that there is:
- Poor or reduced lung function in obese people.
- More inflammation in the fatty tissue under the skin and around internal organs.
Furthermore, the link for Vitamin D hinges with the second reason.
That is - people with obesity who have low Vit D levels have an excessive amount of inflammatory Cytokines which in the case of Covid-19, and this drives more severe disease.
Studies show the role of vitamin D deficiency (low Vit D levels) in immune reactions that leads to a degree of inflammation in fat tissue.
These fatty tissues contain specialised immune cells (lymphocytes and macrophages).
But we have to say that not all scientists think this way.
Some do not agree that all obese people have low Vit D levels or show any sign of low Vit D (like weak bones).
So the debate on this point continues.
Respiratory Infections and Covid-19.
The second reason is a link with respiratory infections which we have briefly addressed.
Studies have demonstrated that Vit D use can protect against respiratory infections - especially in people with severe deficiencies.
These findings are mostly from studies involving the viral infection Influenza.
Scientists are still exploring if the same links exist with other respiratory infections.
Older Age and Covid-19.
Lastly, a recent European study "identified a potential crude association between the mean Vitamin D levels in various European countries" with their COVID-19 cases and deaths.
The study found severely low levels of Vitamin D in countries like Spain, Italy, and Nordic countries; in older people.
These same countries had high Covid-19 infection and death rates, especially among older people.
We know that your Vitamin D status will reduce with age - usually above 70 years of life.
It likely happens from a combination of reduced sun exposure and production of Vit D in the skin.
"The most vulnerable group of the population for Covid-19, the ageing population, is also the one that has the most deficit Vitamin D levels."
So these links with obesity, older age and respiratory infections are possible trends suggesting a link between low Vit D levels and severe Covid-19 disease.
Can We Then Use Vitamin D for Covid-19?
According to a recently (May 1st 2020,) published report by the Center for Evidence-Based Medicine UK, (Vitamin D: A rapid review of the evidence for treatment or prevention in COVID-19)
- Firstly there is yet NO evidence that Vitamin D CURES Covid19.
- Secondly, suggesting that taking Vitamin D will prevent or reduce your risk of getting the Covid19 infection is also as yet unproven.
Should you take Vitamin D supplements?
Yes; but be aware that there is no current, reliable evidence linking the vitamin D to preventing or curing Covid19.
Vitamin D is especially advisable for those who may be at risk of low levels - elderly, melanin skin, inadequate sun exposure etc.
Many studies are going on to determine the answers to these issues.
Meanwhile, It's also important to recall that taking any vitamin in higher quantities than recommended will not provide more significant benefit.
Instead, it could lead to serious side effects (excess blood calcium in the case of Vitamin D) which can harm the heart and kidneys.
Hopefully, this post has given you insights about Vitamin D and it's significant impact in fighting the Covid-19 disease.
Let us know how you feel about these insights down in the comments; would you want to up your dose of Vitamin D or would you rather not?
- Epidemic influenza and vitamin D
- Vitamin D and Influenza—Prevention or Therapy?
- The role of vitamin D in the prevention of coronavirus disease 2019 infection and mortality
- 1alpha,25-Dihydroxyvitamin D3 Is a Potent Suppressor of Interferon Gamma-Mediated Macrophage Activation
- Being male or overweight can lead to more serious COVID-19 hospital admissions
- Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
- Insufficient Vitamin D in Overweight and Obese Children and Adolescents
- Vitamin D: A rapid review of the evidence for treatment or prevention in COVID-19
Editing by AskAwayHealth Team
All AskAwayHealth articles are written by practising Medical Practitioners on a wide range of health care conditions to provide evidence-based guidance and to help promote quality health care. The advice in our material is not meant to replace the management of your specific condition by a qualified health care practitioner.
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