• 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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warning

Early Warning Signs of Serious Health Problems You Should Never Ignore

 

Many serious illnesses do not appear suddenly. They often begin with subtle symptoms that are easy to dismiss. Understanding the early warning signs of serious health problems is essential for timely diagnosis and better treatment outcomes.

According to the World Health Organization and Indian Council of Medical Research (ICMR), early detection significantly reduces mortality from non-communicable diseases such as heart disease, diabetes and cancer. Unfortunately, many individuals delay medical consultation, assuming symptoms will resolve on their own.

Recognising warning signals early can save lives.

 

Why Early Detection Matters

Early diagnosis:

  • improves treatment success

  • reduces complications

  • lowers healthcare costs

  • increases survival rates

Preventive healthcare is more effective than emergency treatment.

 

1. Persistent Chest Pain

Chest discomfort may indicate:

  • heart disease

  • angina

  • lung infection

  • acid reflux

Sudden or recurring chest pain requires immediate medical attention.

Cardiovascular disease remains one of the leading causes of death in India, according to ICMR data.

 

2. Unexplained Weight Loss

Losing weight without dieting or increased activity may signal:

  • thyroid disorders

  • diabetes

  • chronic infections

  • cancer

Unintentional weight loss should always be evaluated.

 

3. Chronic Fatigue

Persistent tiredness that does not improve with rest can indicate:

  • anemia

  • vitamin deficiencies

  • sleep disorders

  • heart problems

  • thyroid imbalance

Fatigue is often underestimated.

 

4. Frequent Headaches

Severe or recurring headaches may signal:

  • hypertension

  • migraine

  • neurological issues

  • brain infection

Sudden, intense headaches require urgent care.

 

5. Shortness of Breath

Difficulty breathing may indicate:

  • asthma

  • chronic obstructive pulmonary disease

  • heart disease

  • anemia

Breathing issues should never be ignored.

 

6. Persistent Fever

Fever lasting more than a few days may indicate:

  • infection

  • tuberculosis

  • autoimmune disease

India continues to report high infectious disease burdens.

 

7. Changes in Bowel or Bladder Habits

Symptoms such as:

  • persistent constipation

  • blood in stool

  • difficulty urinating

may signal digestive or urinary disorders.

 

8. Swelling in Limbs or Face

Swelling may indicate:

  • kidney problems

  • heart failure

  • liver disease

Monitoring fluid retention is important.

 

9. Yellowing of Eyes or Skin

Jaundice indicates:

  • liver dysfunction

  • hepatitis

  • bile duct obstruction

Immediate evaluation is necessary.

 

10. Persistent Cough

A cough lasting more than three weeks may suggest:

  • tuberculosis

  • lung infection

  • chronic respiratory disease

Early diagnosis improves outcomes.

 

Mental Health Warning Signs

Emotional symptoms such as:

  • persistent sadness

  • loss of interest

  • severe anxiety

may indicate depression or anxiety disorders.

Mental health requires equal attention.

 

When to Consult a Doctor

Seek medical attention if:

  • symptoms persist

  • pain intensifies

  • new symptoms develop

  • daily activities are affected

Timely consultation prevents complications.

 

Role of Preventive Health Checkups

Regular screening includes:

  • blood pressure monitoring

  • blood sugar testing

  • lipid profile

  • liver and kidney function tests

NFHS-5 data highlights the increasing burden of lifestyle diseases in India, reinforcing the importance of preventive care.

 

High-Risk Groups

Individuals at higher risk include:

  • those with family history of chronic disease

  • smokers

  • individuals with sedentary lifestyle

  • adults over 40

Proactive screening is essential.

 

Importance of Listening to Your Body

The body often provides early signals before major illness develops. Ignoring these signals delays treatment and increases risk.

Health awareness empowers timely action.

 

Technology and Early Detection

Digital health platforms and teleconsultations allow:

  • early symptom discussion

  • quick medical advice

  • faster referrals

Accessibility improves health outcomes.

 

Conclusion

Recognising early warning signs of serious health problems is one of the most powerful steps toward preventive healthcare. Persistent chest pain, unexplained weight loss, chronic fatigue and breathing difficulties should never be ignored. Early detection saves lives, reduces complications and ensures better recovery outcomes. Regular health checkups and timely medical consultation remain the foundation of long-term wellbeing.

Taking action at the first sign of concern can make the difference between simple treatment and serious complications.

 

References

Indian Council of Medical Research (ICMR) – Non-Communicable Disease Reports
National Family Health Survey (NFHS-5) – Adult Health Indicators
World Health Organization (WHO) – Early Detection and Screening Guidelines
NITI Aayog – Preventive Healthcare Strategy Reports
Lancet – Chronic Disease and Early Diagnosis Research

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