• 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
Digital Health Platforms in India: Building the Future of Connected Care | SecondMedic

Digital Health Platforms in India: Building the Future of Connected Care | SecondMedic

Healthcare in India is no longer limited to clinics and hospitals — it’s now in your pocket.
From booking doctor consultations to receiving AI-analyzed reports, digital health platforms have redefined how healthcare works across India.

And leading this change is SecondMedic, a one-stop digital platform that connects patients, doctors, and diagnostics into a unified care experience.

 

India’s Digital Healthcare Revolution

Over the last five years, India has witnessed an unprecedented surge in digital health adoption.
According to NITI Aayog (2025), India’s digital health market is projected to touch USD 12.5 billion by 2026, driven by government initiatives and private innovation.

The Ayushman Bharat Digital Mission (ABDM) has further accelerated this growth by creating unique Health IDs for citizens and standardizing digital health records (ABDM Official Portal).

“India’s digital health transformation is not just technological — it’s social,” says Dr. Meenakshi Sharma, Chief Health Officer, SecondMedic.
“We’re closing the gap between care availability and accessibility.”

 

How Digital Health Platforms Are Changing the Game

  1. Unified Access to Care
    Users can consult doctors, order medicines, and view lab results — all from one dashboard.
     

  2. AI-Driven Diagnostics
    Machine learning enhances test interpretation, providing faster and more accurate results.
     

  3. Preventive Health Focus
    Platforms like SecondMedic encourage early detection with annual screenings and wellness tracking.
     

  4. Telemedicine & Remote Monitoring
    With over 850 million internet users (TRAI 2025), even rural India now enjoys access to quality virtual care.
     

  5. Health Data Integration
    Digital records make cross-specialty consultations efficient and error-free.
     

 

SecondMedic’s Digital Health Platform

SecondMedic integrates all aspects of healthcare — digital consultations, diagnostics, e-pharmacy, and preventive programs — into one intelligent ecosystem.

Key Features:

  • AI-based diagnostic analysis
     

  • Virtual consultations with specialists
     

  • Home sample collection
     

  • Digital health record management
     

  • Personalized preventive care insights
     

The result?
A smoother, faster, and more transparent healthcare journey for every Indian.

 

The Numbers Speak

  • NASSCOM (2025): 70% of Indian healthcare providers now use digital tools.
     

  • WHO India (2024): Digitalization can save USD 4 billion annually in system inefficiencies.
     

  • IMARC Group (2025): 25% of outpatient visits now happen through telemedicine.
     

  • SecondMedic data (2025): 80% of users completed their entire healthcare journey digitally — from diagnosis to medication.
     

 

The Future of Digital Health Platforms

With rapid 5G rollout, IoT wearables, and growing AI adoption, India’s digital health platforms are entering their most transformative phase yet.

Soon, patients will receive predictive health alerts, automated prescriptions, and real-time vitals monitoring — enabling truly proactive healthcare.

And with leaders like SecondMedic, this revolution will be accessible to everyone — not just the privileged few.

 

Conclusion

The rise of digital health platforms in India marks a new era of connected, patient-first healthcare.
By integrating technology, innovation, and empathy, SecondMedic is turning that vision into reality — one digital interaction at a time.

Because in a connected world, good health shouldn’t wait.

Explore smarter healthcare today at www.secondmedic.com

 

Real Data & References

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