• 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

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Yellowing

Yellow Eyes and Skin Symptoms: Causes, Warning Signs and When to Seek Care

Yellowing of the eyes and skin is one of the most noticeable physical changes a person can experience. Often referred to as jaundice, this symptom is not a disease by itself but a sign of underlying health conditions. Understanding yellow eyes and skin symptoms is essential because they frequently indicate problems involving the liver, blood or bile ducts and may require urgent medical attention.

In India, jaundice is a common presentation across age groups due to infections, liver disease and metabolic disorders.

 

What Does Yellowing of Eyes and Skin Mean?

The yellow colour appears due to excess bilirubin in the blood.

Bilirubin is:

  • a yellow pigment

  • produced from the breakdown of red blood cells

  • processed and removed by the liver

When bilirubin builds up, it deposits in tissues, causing yellow discoloration.

 

Why the Eyes Turn Yellow First

The sclera, or white part of the eyes, contains elastic tissue that binds bilirubin easily.

This makes yellowing:

  • more visible in eyes

  • detectable before skin changes

Yellow eyes are often the earliest sign of jaundice.

 

Common Causes of Yellow Eyes and Skin

Liver-Related Causes

The liver plays a central role in bilirubin metabolism.

Common liver causes include:

  • viral hepatitis (A, B, C, E)

  • fatty liver disease

  • alcoholic liver disease

  • liver cirrhosis

  • drug-induced liver injury

ICMR reports viral hepatitis as a major cause of jaundice in India.

 

Bile Duct Obstruction

Blocked bile flow prevents bilirubin excretion.

Causes include:

  • gallstones

  • bile duct strictures

  • pancreatic or bile duct tumours

This type of jaundice is often associated with itching and pale stools.

 

Blood Disorders

Excess breakdown of red blood cells increases bilirubin production.

Conditions include:

  • hemolytic anemia

  • malaria

  • inherited blood disorders

The liver may be overwhelmed despite being healthy.

 

Infections

Certain infections directly affect liver function.

Examples include:

  • hepatitis viruses

  • leptospirosis

  • severe sepsis

WHO data highlights hepatitis as a leading infectious cause of jaundice globally.

 

Newborn and Pregnancy-Related Causes

While common in newborns, jaundice in adults always needs evaluation.

Pregnancy-related liver disorders can also cause yellowing.

 

Associated Symptoms That Provide Clues

Yellow eyes and skin are often accompanied by:

  • dark yellow or tea-coloured urine

  • pale or clay-coloured stools

  • itching

  • fatigue

  • abdominal pain

  • loss of appetite

These symptoms help identify the underlying cause.

 

When Yellowing Becomes Dangerous

Seek urgent medical care if yellowing is accompanied by:

  • high fever

  • severe abdominal pain

  • confusion or drowsiness

  • vomiting

  • rapid worsening of colour

These signs suggest severe liver or systemic disease.

 

Jaundice and Liver Function

The liver normally:

  • conjugates bilirubin

  • excretes it into bile

When liver cells are damaged, bilirubin accumulates.

Lancet studies confirm jaundice as a key marker of liver dysfunction.

 

Diagnostic Evaluation

Doctors evaluate jaundice using:

  • blood tests for bilirubin levels

  • liver function tests

  • viral markers

  • ultrasound or CT scans

  • additional tests based on findings

Early testing identifies reversible causes.

 

Impact on Daily Life

Persistent jaundice can affect:

  • energy levels

  • digestion

  • mental clarity

  • work performance

Untreated liver disease can progress silently.

 

Treatment Depends on the Cause

There is no single treatment for jaundice.

Management focuses on:

  • treating infection

  • relieving bile obstruction

  • stopping harmful medications

  • managing chronic liver disease

Self-medication can worsen liver injury.

 

Role of Preventive Healthcare

Preventive measures include:

  • hepatitis vaccination

  • safe drinking water

  • limiting alcohol intake

  • regular health checkups

NITI Aayog emphasises liver health in preventive care strategies.

 

Lifestyle Factors That Affect Liver Health

Risk factors include:

  • excessive alcohol

  • obesity

  • high-fat diets

  • unsafe injections

Addressing these reduces jaundice risk.

 

Importance of Early Detection

Early diagnosis:

  • prevents complications

  • improves recovery

  • reduces hospitalisation

Delays increase the risk of liver failure.

 

Jaundice Is a Symptom, Not a Diagnosis

Understanding this distinction is crucial.

Treating the symptom alone:

  • does not resolve the disease

  • may mask serious conditions

Medical evaluation is essential.

 

Conclusion

Yellow eyes and skin symptoms are visible warning signs that should never be ignored. Most often linked to jaundice, they reflect underlying problems involving the liver, bile ducts or blood. Early medical evaluation, accurate diagnosis and timely treatment are critical to prevent serious complications. Recognising these symptoms and seeking care promptly can protect liver health and save lives.

 

References

  • Indian Council of Medical Research (ICMR) – Hepatitis and Liver Disease Reports

  • World Health Organization (WHO) – Jaundice and Hepatitis Guidelines

  • National Family Health Survey (NFHS-5) – Liver and Metabolic Health Indicators

  • Lancet – Liver Function and Bilirubin Research

  • NITI Aayog – Non-Communicable Diseases and Liver Health

  • Statista – Liver Disease and Hepatitis Trends

See all

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