• 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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Weekly Health Roundup Newsletter: India’s Trusted Source for Preventive Wellness Insights

Weekly Health Roundup Newsletter: India’s Trusted Source for Preventive Wellness Insights

Health information today is abundant, but not always reliable. With countless articles, social media trends, home remedies and conflicting opinions, individuals often struggle to separate credible medical advice from misinformation. This challenge becomes especially significant in India, where rising lifestyle diseases, nutritional gaps and limited public health awareness create a pressing need for accurate guidance.

The Weekly Health Roundup Newsletter by SecondMedic addresses this gap by offering a clear, expert-driven and accessible summary of everything people need to know about their health each week. Designed for families, patients, caregivers and wellness-focused readers, it transforms medical updates into practical, everyday insights.

 

Why India Needs a Weekly Health Roundup

1. Growing Lifestyle Disease Burden

ICMR and NFHS-5 highlight significant increases in:

  • Diabetes

  • Heart disease

  • Thyroid disorders

  • Obesity

  • PCOS
     

A weekly educational resource empowers individuals to make preventive choices before complications arise.

2. Overload of Health Information

Millions of Indians rely on social media for health advice, leading to confusion and misinformation.
A curated newsletter ensures accuracy.

3. Rising Interest in Preventive Healthcare

People want to understand their bodies better, track health metrics and adopt healthier lifestyles.
The newsletter provides guidance supported by medical evidence.

4. Technological Growth in Healthcare

AI-based tools, wearables and digital monitoring are reshaping healthcare.
Readers learn how to use them effectively.

 

What the Weekly Health Roundup Covers

• Medical Research Summaries

Digestible versions of new findings from:

  • ICMR

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  • Lancet

  • NITI Aayog

  • Global medical journals
     

• Nutrition and Lifestyle Guidance

Includes:

  • Balanced diets

  • Myth-busting

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• Chronic Disease Management Tips

Expert insights on:

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• Mental Wellbeing

Stress reduction, emotional resilience and sleep optimisation tips.

• Fitness Recommendations

Simple routines, mobility tips, strength guidance and step-based activity recommendations.

• Seasonal Health Alerts

Information on:

  • Pollution

  • Heatwaves

  • Monsoon infections

  • Viral outbreaks
     

• Digital Health Education

Guidance on:

  • AI health tools

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  • Remote monitoring
     

 

How SecondMedic Ensures Accuracy and Quality

Expert Verification

Doctors, nutritionists, physiotherapists and mental health specialists review every issue.

Evidence-Based Approach

Content uses:

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Personalised Relevance

Topics are selected based on what Indian families most commonly search, ask or struggle with.

Preventive Care Focus

Instead of addressing illness alone, the newsletter promotes long-term lifestyle improvement.

 

How Readers Benefit

1. Improved Health Literacy

People understand conditions earlier and seek help at the right time.

2. Practical, Actionable Advice

The newsletter offers:

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3. Early Detection Support

By recognizing symptoms and risk patterns, individuals can prevent complications.

4. Better Use of Digital Tools

Readers learn how AI health guides and wearables support monitoring and early intervention.

5. Family-Centered Wellness

Content is relevant to:

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Example Weekly Topics

A sample edition may include:

  • "New Findings on Vitamin D Deficiency in Indian Adults"

  • "How to Interpret Your Blood Sugar Patterns"

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  • "Early Signs of Heart Disease You Shouldn’t Ignore"

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Conclusion

The Weekly Health Roundup Newsletter is more than just a health update-it is a practical wellness companion. With expert insights, scientific clarity and personalised relevance, it empowers people across India to make smarter health decisions every week.

By turning complex medical knowledge into everyday guidance, SecondMedic strengthens India’s preventive healthcare movement one newsletter at a time.

 

References

• ICMR - Lifestyle Disease Burden & Research Updates
• NFHS-5 - National Health Indicators & Wellness Trends
• NITI Aayog - Digital Health & Preventive Care Framework
• WHO - Global Wellness & Preventive Healthcare Guidelines
• Lancet - Public Health Research & Behaviour Studies
• Statista India - Digital Health Usage & Reader Behaviour
• EY-FICCI - Health Awareness & Preventive Care Landscape

See all

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