• 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
Asthma

Asthma Symptoms in Adults: Early Signs, Triggers, and When to Seek Care

Asthma is often perceived as a childhood condition, but a significant number of cases develop or persist into adulthood. In India, adult asthma is increasingly recognised due to rising air pollution, occupational exposure and lifestyle-related risk factors. Unfortunately, asthma symptoms in adults are frequently misdiagnosed as recurrent infections, allergies or age-related breathlessness, leading to delayed treatment.

Understanding adult asthma symptoms is critical for early diagnosis, effective control and prevention of severe attacks.

 

What Is Asthma?

Asthma is a chronic inflammatory disease of the airways. In asthma, the airways become:

  • inflamed
     

  • narrow
     

  • overly sensitive to triggers
     

This leads to difficulty in breathing, especially during exposure to specific stimuli.

 

Why Adult Asthma Is Often Missed

Adult asthma symptoms may:

  • appear gradually
     

  • vary in severity
     

  • mimic common respiratory conditions
     

According to Indian Council of Medical Research and WHO data, many adults remain undiagnosed for years, increasing the risk of complications.

 

Common Asthma Symptoms in Adults

Wheezing

A high-pitched whistling sound while breathing, especially during exhalation, is a classic asthma sign.

 

Shortness of Breath

Adults with asthma often feel:

  • breathless during routine activities
     

  • difficulty taking deep breaths
     

This may worsen at night or early morning.

 

Chest Tightness

Many describe a sensation of pressure or tightness in the chest, which can be mistaken for heart-related issues.

 

Chronic Cough

A persistent cough, especially:

  • at night
     

  • early morning
     

  • after exercise
     

is a common but overlooked asthma symptom.

 

Symptoms That Worsen With Triggers

Asthma symptoms often intensify after exposure to specific triggers.

Air Pollution and Smoke

Urban pollution, vehicle emissions and indoor smoke significantly worsen asthma symptoms in adults.

 

Allergens

Dust mites, pollen, mould and pet dander are common triggers.

 

Respiratory Infections

Viral infections can trigger asthma flare-ups or reveal undiagnosed asthma.

 

Physical Activity

Exercise-induced asthma causes breathlessness and wheezing during or after physical exertion.

 

Weather Changes

Cold air, humidity and sudden temperature changes can aggravate symptoms.

 

Adult-Onset Asthma

Adult-onset asthma differs from childhood asthma.

Characteristics include:

  • onset after age 20–30
     

  • less association with childhood allergies
     

  • more persistent symptoms
     

  • higher likelihood of severe disease
     

Occupational exposure and hormonal changes contribute to adult-onset asthma.

 

Risk Factors for Asthma in Adults

Several factors increase asthma risk:

  • long-term exposure to pollution
     

  • smoking or passive smoking
     

  • occupational chemicals or dust
     

  • obesity
     

  • family history of asthma
     

  • chronic sinusitis or allergies
     

Women may experience asthma onset or worsening during hormonal changes.

 

When Asthma Symptoms Become Serious

Seek immediate medical attention if experiencing:

  • severe breathlessness
     

  • difficulty speaking in full sentences
     

  • bluish lips or fingertips
     

  • rapid worsening of symptoms
     

  • poor response to usual inhalers
     

These signs indicate a potentially life-threatening asthma attack.

 

How Adult Asthma Is Diagnosed

Diagnosis includes:

  • detailed symptom history
     

  • physical examination
     

  • lung function tests (spirometry)
     

  • response to bronchodilators
     

Early diagnosis improves long-term outcomes.

 

Impact of Untreated Asthma

Untreated asthma can lead to:

  • frequent attacks
     

  • reduced lung function
     

  • sleep disturbances
     

  • missed workdays
     

  • reduced quality of life
     

According to Lancet respiratory studies, uncontrolled asthma increases hospitalisation risk.

 

Managing Asthma Symptoms in Adults

Effective asthma management focuses on:

  • identifying and avoiding triggers
     

  • using prescribed inhalers correctly
     

  • monitoring symptoms regularly
     

  • maintaining follow-up care
     

Asthma action plans help patients recognise worsening symptoms early.

 

Role of Preventive Healthcare

Preventive healthcare helps:

  • detect asthma early
     

  • assess lung function
     

  • guide lifestyle modifications
     

Regular health checkups are especially important for individuals with respiratory symptoms or occupational exposure.

 

Lifestyle Measures That Support Asthma Control

Helpful practices include:

  • avoiding smoking
     

  • improving indoor air quality
     

  • wearing masks in polluted environments
     

  • maintaining healthy weight
     

  • regular, moderate exercise
     

Lifestyle support complements medical treatment.

 

Mental Health and Asthma

Stress and anxiety can worsen asthma symptoms.

Stress management:

  • reduces symptom frequency
     

  • improves medication response
     

Holistic care improves asthma outcomes.

 

Importance of Medication Adherence

Asthma medications work best when:

  • taken regularly as prescribed
     

  • inhaler technique is correct
     

Skipping treatment increases flare-up risk.

 

Long-Term Outlook for Adults With Asthma

With proper management:

  • symptoms are well controlled
     

  • severe attacks are preventable
     

  • normal activity levels are achievable
     

Most adults with asthma lead active, productive lives.

 

Conclusion

Asthma symptoms in adults are often subtle, variable and easily mistaken for common respiratory problems. Wheezing, breathlessness, chest tightness and chronic cough should not be ignored, especially when triggered by pollution, exercise or weather changes. Early diagnosis, trigger control and consistent treatment are essential to prevent severe attacks and preserve lung health. Recognising adult asthma early empowers individuals to manage symptoms effectively and maintain a good quality of life.

 

References

  • Indian Council of Medical Research (ICMR) – Respiratory Disease and Asthma Studies
  • World Health Organization (WHO) – Asthma Management and Prevention Guidelines
  • National Family Health Survey (NFHS-5) – Respiratory Health Indicators
  • Lancet Respiratory Medicine – Adult Asthma Outcomes and Management
  • NITI Aayog – Air Pollution and Respiratory Health Reports
  • Statista – Global Asthma Prevalence and Trends

See all

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