• 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
Food Poisoning in Monsoon

How to Prevent Food Poisoning in Monsoon

Monsoon brings relief from the heat—but along with cool breezes and rains come increased chances of infections, especially food poisoning. The high moisture in the air creates a perfect breeding ground for bacteria, making food more likely to spoil and cause illness.

In this article, we’ll help you understand how to stay safe with easy, practical tips on how to prevent food poisoning in monsoon.

 

Why Is Food Poisoning So Common in Monsoon?

The damp and humid conditions during the rainy season promote bacterial and fungal growth. This contamination can easily affect the food we eat and the water we drink.

Common causes of food poisoning in monsoon include:

  • Eating contaminated street food
     

  • Drinking unfiltered or untreated water
     

  • Improper storage or refrigeration
     

  • Eating undercooked or reheated leftovers
     

Symptoms can range from mild stomach pain to vomiting, diarrhea, and fever—and can become serious if not treated on time.

 

How to Prevent Food Poisoning in Monsoon: Easy Tips

Let’s go step by step into what you should do (and not do) during this season to avoid foodborne illness:

 

1. Avoid Street Food and Raw Salads

Street vendors often use unclean water and keep food exposed to dust, flies, and pollution. In monsoon, this risk becomes even higher.

What to avoid:

  • Chaat, golgappas, sandwiches from carts
     

  • Cut fruits or raw vegetables sold outside
     

  • Juices from roadside stalls
     

Instead, eat home-cooked meals where you can control the hygiene.

 

2. Drink Only Boiled or Purified Water

Unfiltered water is a major cause of stomach infections during monsoon. Make sure your drinking water is:

  • Boiled for 10 minutes, or
     

  • Filtered using a RO/UV purifier, or
     

  • Packaged from a trusted brand
     

Avoid consuming water-based drinks like sherbets or ice made with unclean water.

 

3. Eat Fresh and Hot Food

In monsoon, bacteria multiply quickly. Avoid eating food that has been left out for hours.

Tips:

  • Eat freshly cooked meals while still warm
     

  • Avoid reheating food multiple times
     

  • Don't leave cooked food at room temperature for more than 2 hours
     

 

4. Refrigerate Perishables Quickly

Your fridge is your best friend in this season—but only if you use it right.

Refrigeration tips:

  • Store cooked food in airtight containers
     

  • Don't keep raw meat and vegetables together
     

  • Use leftovers within 24 hours
     

  • Check for expired or spoiled food regularly
     

 

5. Clean Fruits and Vegetables Properly

Rainwater often brings mud and germs to fresh produce. Even greens from the market can carry bacteria and insect eggs.

Cleaning tips:

  • Wash produce thoroughly with clean water
     

  • Use salt water or vinegar soak for 10–15 minutes to disinfect
     

  • Peel fruits like mangoes and bananas before eating
     

  • Avoid leafy vegetables that are difficult to clean, like spinach and lettuce
     

 

6. Practice Good Kitchen Hygiene

Contamination often starts in your kitchen.

Hygiene habits to follow:

  • Wash hands before and after handling food
     

  • Keep utensils and chopping boards dry and clean
     

  • Don't let water collect on kitchen surfaces
     

  • Wash dish cloths and sponges regularly
     

 

Related Health Checkups to Consider

If you're experiencing stomach problems or want to monitor your digestive health during monsoon, these lab tests (available via SecondMedic powered by Thyrocare) may help:

???? Complete Blood Count (CBC)

Checks for infections or inflammation.

???? Stool Routine & Culture Test

Detects bacterial infections, parasites, or digestive disorders.

???? CRP Test (C-Reactive Protein)

Shows whether your body is fighting an infection.

???? Food Intolerance Test

For people with recurring food-related digestive issues.

All tests come with home sample collection and online report access at www.secondmedic.com.

 

Foods You Can Eat During Monsoon

Here are some healthy, safe food choices during the rainy season:

  • Warm soups and khichdi – light and easy to digest
     

  • Steamed vegetables – safer than raw
     

  • Ginger tea – helps digestion
     

  • Turmeric milk – natural immunity booster
     

  • Boiled eggs or well-cooked lean meat
     

Avoid oily, uncooked, or refrigerated food that’s more than a day old.

 

Conclusion

Monsoon brings beauty, but also bacteria. Staying safe is all about being smart with your food and water. By following simple hygiene rules and eating fresh, clean food, you can enjoy the season without worrying about stomach issues.

Be alert, eat smart, and protect your family by following these tips on how to prevent food poisoning in monsoon.

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