• Published on: Apr 17, 2020
  • 4 minute read
  • By: Dr Rajan Choudhary

Vitamin D In Reducing The Risk Of COVID 19

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Why Vitamin D is the only supplement we will recommend for you.

Most of our blogs have looked at theories posted on social media, and shown how they are usually not true, or have no factual basis behind them. But here we will show some evidence that supports something truly interesting, especially during the time of this pandemic.

For a number of years research has shown a possible link between vitamin D and illnesses, specifically respiratory infections. In our previous blogs we have shown that vitamin supplementation is unnecessary, except for vitamin D. Here we will show why supplementation may be in your best interest for reducing the risk of COVID.

Now I’ll be honest. Vitamin D and immunity was not something we were taught at medical school, or in medical practice. The fact that such a large amount of research exists on this topic is certainly interesting, and whilst researching this topic I have certainly learnt a lot myself, enough to change my own medical practice. And it is because of the high quality of evidence present that I feel confident in supporting the claims below.

SUMMARY

  • Many people are low in Vitamin D due to various risk factors (see our blog on vitamin D)
  • Vitamin D appears to have a role in modulating immune function
  • Low Vitamin D levels appear to increase the severity of autoimmune disorders
  • Low Vitamin D levels appear to increase the risk of getting respiratory infections
  • Vitamin D supplementation appears to reduce the risk of getting respiratory infections
  • Those who are at risk of having low vitamin D should take low dose supplementations.

If you want the good stuff, skip to the section on SUPPLEMENTATION

IMMUNE FUNCTIONS

As we’ve discussed, vitamin D is key in maintaining the right balance of calcium, ensuring the right amount is taken up from the food we eat, integrated into our bones, and removed in our urine if not required. We know that there are some people who are at risk of vitamin D deficiency, and this is more common in countries closer to the poles and with cloudy weather.

But there also appears to be a role for vitamin D in modulating the immune system. We have found many more cells in our body other than bone, intestine and kidney that possess the vitamin D receptor. These include immune cells, and one role may be to promote proliferation of these cells as well as promote their protective immunity.

AUTOIMMUNE

Due to its role in immune function, studies have been performed to see whether there is a link between autoimmune diseases and vitamin D. Common autoimmune disorders (and the organs the affect) include multiple sclerosis (nerves), rheumatoid arthritis (joints), diabetes mellitus (pancreas), inflammatory bowel disease (bowels) and systemic lupus erythematous (the entire body). All of these diseases lead to loss in function of an organ or system as the immune system recognises the organ as an “invader” and begins to destroy it.

One study looked at 161 patients with early forms of autoimmune diseases over 2 years. Out of them, 35 went on to develop full blown autoimmune disorders (like rheumatoid and lupus). Whilst the two groups of patients were mostly similar, vitamin D was noticeably lower in the group that progressed to disease. But this is one study, with a small number of patients.

Other studies have looked at vitamin D levels in patients across the globe, and the majority of them have shown there to be a correlation between low vitamin D or severe deficiency, and the severity of autoimmune disorder they have. We will not go into them in detail because this is beyond the scope of this blog, but it certainly is interesting and supports this new role for vitamin D.

RESPIRATORY INFECTIONS

We have unknowingly tried to use Vitamin D to treat infections prior to the advent of antibiotics. A common treatment for tuberculosis was to send patients to sanatoriums, where treatments included exposure to sunlight, and provision of cod liver oil, a rich source of vitamin D.

Large population studies done in the 1980s and 1990s involving 19,000 people showed that those with low vitamin D levels were more likely to self report recent upper respiratory tract infections than those with normal levels. This was true even if age, gender, season and race were accounted for. Similar studies have shown similar results when looking at rates of influenza, bacterial vaginosis and HIV.

Normally we are very skeptical with such studies, and look for weaknesses in their methodology and conclusions. After all, we could just cherry pick the studies that show a benefit. Furthermore, just because there is a trend with vitamin D levels and infection, this does not imply a direct link. More evidence is required. However, the fact 19,000 people were surveyed provides this study with good statistical power, and lends it validity. But lets look for more.

SUPPLEMENTATION

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data – Martineau 2017, British Medical Journal

A systematic review and meta analysis is the highest level of evidence in the realm of medical research. It is the absolute pinnacle of thorough research, looking and comparing other studies with very close scrutiny to see whether we have conducted enough research worldwide to support a theory. In this case this systematic review was published in the British Medical Journal, a highly reputable source that again scrutinises any study submitted thoroughly before accepting it for publication. In my eyes, this is some of the best evidence we will have on this topic. And it is a far sight better than any WhatsApp forwards.

So what does this say?

Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.

I don’t think I could have summarised it better myself. If you wish to read the study yourself you can use this link: https://www.bmj.com/content/356/bmj.i6583 Vitamin D supplementation to prevent acute respiratory tract infections

WHAT DOES THIS MEAN FOR ME?

If you are someone who may be at risk of vitamin D deficiency, then low dose supplements (NOT treatment dose) may be beneficial in reducing the risk of getting a respiratory infection. Since COVID is caused by a respiratory virus, we can extrapolate that Vitamin D supplementations may reduce your risk of getting COVID. This is not a cure, and it is not a guaranteed protection. If you already have a balanced diet and are not low in Vit D, it may be less beneficial.

Dr Rajan Choudhary, UK, Chief Product Officer, Second Medic Inc

www.secondmedic.com

Read Blog
Inflammation

How Inflammation Affects Overall Health: Understanding the Hidden Risks

Inflammation is often misunderstood. While it is a vital protective response of the immune system, persistent or chronic inflammation can quietly damage tissues and increase the risk of serious diseases. Understanding how inflammation affects overall health is crucial in preventing long-term complications and maintaining optimal wellbeing.

According to the World Health Organization and global medical research published in Lancet, chronic inflammation is linked to a wide range of non-communicable diseases, including heart disease, diabetes and autoimmune disorders.

 

What Is Inflammation?

Inflammation is the body’s natural response to:

  • infection

  • injury

  • toxins

  • stress

It activates immune cells to eliminate harmful stimuli and promote healing.

There are two main types:

Acute Inflammation

Short-term and protective.
Examples include swelling after injury or fever during infection.

Chronic Inflammation

Long-term, low-grade inflammation that persists even without injury.

Chronic inflammation is harmful.

 

How Chronic Inflammation Develops

Persistent inflammation can result from:

  • unhealthy diet

  • sedentary lifestyle

  • obesity

  • chronic stress

  • environmental toxins

  • untreated infections

Modern lifestyle patterns contribute significantly to this condition.

 

Impact on Heart Health

Inflammation damages blood vessels and promotes plaque formation.

This increases risk of:

  • heart attack

  • stroke

  • hypertension

ICMR data highlights cardiovascular disease as a leading cause of death in India, with inflammation playing a contributing role.

 

Link Between Inflammation and Diabetes

Chronic inflammation interferes with insulin signalling.

This leads to:

  • insulin resistance

  • elevated blood sugar

  • metabolic syndrome

NFHS-5 data shows rising diabetes prevalence, partly linked to inflammatory lifestyle factors.

 

Effect on Joint and Muscle Health

Inflammatory processes contribute to:

  • arthritis

  • joint stiffness

  • muscle pain

Autoimmune diseases often involve chronic inflammation.

 

Gut Health and Inflammation

The gut plays a central role in immune regulation.

Poor diet and stress disrupt gut balance, triggering:

  • inflammatory bowel conditions

  • digestive discomfort

  • nutrient malabsorption

Gut inflammation impacts systemic health.

 

Brain Health and Inflammation

Emerging research suggests chronic inflammation affects:

  • memory

  • mood

  • cognitive performance

Inflammatory markers are associated with depression and neurodegenerative disorders.

 

Chronic Fatigue and Inflammatory Stress

Persistent inflammation causes:

  • ongoing fatigue

  • reduced stamina

  • sleep disturbances

The immune system remains in constant activation mode.

 

Role in Autoimmune Disorders

Autoimmune diseases occur when the immune system mistakenly attacks healthy tissues.

Chronic inflammation is central to conditions such as:

  • rheumatoid arthritis

  • lupus

  • inflammatory bowel disease

 

Signs of Chronic Inflammation

Symptoms may include:

  • unexplained fatigue

  • persistent joint pain

  • digestive issues

  • frequent infections

  • skin problems

Early detection is important.

 

Lifestyle Factors That Increase Inflammation

High Sugar Intake

Excess sugar promotes inflammatory pathways.

 

Processed Foods

Trans fats and additives trigger immune responses.

 

Sedentary Lifestyle

Lack of exercise reduces anti-inflammatory benefits.

 

Poor Sleep

Sleep deprivation increases inflammatory markers.

 

Chronic Stress

Elevated cortisol disrupts immune balance.

 

Natural Ways to Reduce Inflammation

Anti-Inflammatory Diet

Include:

  • leafy greens

  • fruits rich in antioxidants

  • nuts and seeds

  • whole grains

Avoid excessive processed foods.

 

Regular Physical Activity

Exercise lowers inflammatory markers and improves circulation.

 

Stress Management

Meditation and breathing exercises reduce stress hormones.

 

Adequate Sleep

7–8 hours of quality sleep supports immune regulation.

 

Maintain Healthy Weight

Excess abdominal fat produces inflammatory chemicals.

 

Role of Preventive Health Screening

Regular tests such as:

  • blood sugar

  • lipid profile

  • inflammatory markers

help monitor risk factors early.

 

Importance of Early Intervention

Unchecked inflammation increases risk of:

  • cardiovascular disease

  • metabolic disorders

  • organ damage

Timely lifestyle changes reverse early inflammatory effects.

 

Long-Term Health Benefits of Inflammation Control

Reducing inflammation supports:

  • heart health

  • stable blood sugar

  • improved immunity

  • enhanced cognitive function

  • reduced pain

Preventive strategies protect long-term wellbeing.

 

Conclusion

Understanding how inflammation affects overall health reveals its profound impact on the heart, brain, gut and metabolic systems. While acute inflammation protects the body, chronic inflammation silently contributes to major diseases. Fortunately, lifestyle changes such as balanced nutrition, regular exercise, quality sleep and stress management significantly reduce inflammatory burden. Prevention and early monitoring remain the most effective tools for protecting overall health and ensuring long-term vitality.

 

References

  • World Health Organization (WHO) – Chronic Disease and Inflammation Reports

  • Indian Council of Medical Research (ICMR) – Cardiovascular and Metabolic Health Studies

  • National Family Health Survey (NFHS-5) – Diabetes and Hypertension Data

  • NITI Aayog – Preventive Healthcare Strategy Reports

  • Lancet – Inflammation and Chronic Disease Research

See all

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