Covid-19 and vitamin D
COVID-19Vitamin D

Covid-19 and vitamin D

Covid-19 and vitamin D

November 19, 2020

Since the coronavirus pandemic hit, vitamin D has been big news. This is because studies suggest that if you don’t have enough vitamin D, you may be more likely to develop more severe symptoms of Covid-19.But what does vitamin D do, and will it really stop you from getting Covid-19?

Since the coronavirus pandemic hit, vitamin D has been big news. This is because studies suggest that if you don’t have enough vitamin D, you may be more likely to develop more severe symptoms of Covid-19.

But what does vitamin D do, and will it really stop you from getting Covid-19?

So, what is vitamin D, and why is it important?

Our bodies make vitamin D when our skin is exposed to sunlight. When we’re outside and the sun is shining, our body will naturally produce vitamin D. You can also get vitamin D from some foods like oily fish (e.g. salmon, mackerel), eggs, fortified fat spreads, fortified breakfast cereals, and red meat.

“Ideally, this should give us all the vitamin D we need”, says Dr Kush Joshi, UK medical lead for Melio, “but data shows 1 in 5 people in the UK are severely deficient and I think it’s many more than that. In the northern hemisphere, the winter sun is not strong enough for anyone to make enough vitamin D, and you could argue we don’t get sufficient sunlight during the summer months either.”

There are other factors that can affect how much vitamin D you’re making, including:

  • Having a darker skin tone.

  • Covering your skin for cultural reasons.

  • Covering your skin for health reasons.

On top of that, past campaigns to get everyone to use sun cream, and protect themselves against skin damage from the sun, have done such a good job, many of us are now not making enough vitamin D even when we are exposed to the sun.

Covid-19 has brought this issue into focus, and could have made it worse, Dr Joshi says:

“This is even more of an issue at the moment when we’ve had one million people in the UK who have shielded over the summer, and many people are having to self-isolate because of COVID-19. Plus if you are working from home you won’t even be getting the small amount of exposure to sunlight you would have had from going out to work.”

While you can get vitamin D from your diet, it’s hard for most people to get enough from food alone, which is why Public Health England (PHE) updated its guidance on vitamin D in April to recommend that everyone takes a daily supplement of 10µg1.

What does vitamin D do?

Vitamin D helps the body absorb calcium from food and supplements. It regulates the amount of calcium and phosphate needed to keep bones and teeth healthy and maintain strong muscles.

As we’ve said, vitamin D is also essential for our immune function. The immune system defends the body from foreign, invading organisms such as allergens, bacteria and viruses.

If you have low vitamin D, you can be more susceptible to infection, as well as increased autoimmunity (when the immune system ‘attacks’ the body). You can address both by supplementing with vitamin D.

What can happen if you have low vitamin D?

Although having low vitamin D levels is a common problem in the UK, most people don't know if they are in the risk zone.

Worryingly, the most recent National Diet and Nutrition Survey (NDNS) data shows that 29% of adults aged 19-64 have a vitamin D deficiency, which puts them at risk of developing a number of illnesses and conditions type 2 diabetes, chronic pain, osteoporosis as well as increasing the risk of obesity.

At the extreme end of the scale, this includes rickets in children and adolescents, and osteomalacia in adults – painful conditions where bones become soft and deformed due to calcium reabsorption from the bones .

Risk of respiratory tract infection

As well as the illnesses already mentioned, low vitamin D levels are associated with an increased risk of respiratory tract infection.

Recent studies have shown people with lower vitamin D levels were more likely to report having had an upper respiratory tract infection (URTI) than those with normal levelsiv - this is especially true in children.

Vitamin D and Covid-19

So, does vitamin D really protect against Covid-19?

Back in June, England’s National Institute for Health and Care Excellence (NICE) conducted a rapid evidence summary, in response to claims that vitamin D may have a role in preventing or treating COVID-19. It concluded that there was “no evidence to support taking vitamin D supplements to specifically prevent or treat COVID-19” but suggested that “all people should continue to follow UK Government advice on daily vitamin D supplementation to maintain bone and muscle health during the COVID-19 pandemic”.

However, in August, another review of the preliminary evidence that COVID-19 risk and severity is increased if you have low vitamin D suggested that because our immune system is impaired by vitamin D deficiency, this would predispose sufferers to viral infections like COVID-19.

This review also claimed that because vitamin D deficiency increases the activity of the ‘Renin-Angiotensin’ System, this makes people who are vitamin D deficient (especially men) more likely to have an immune system overreaction caused by COVID-19, called a ‘cytokine storm’.

The review said that the same people who are at highest risk for severe COVID-19 match those who are at highest risk for severe vitamin D deficiency, including the elderly, men, ethnic groups with darker skin, people who avoid sun exposure for cultural and health reasons, people who are obese, and/or those who suffer with hypertension, cardiovascular disease, or diabetes.

While research continues to investigate the role of vitamin D supplements during recovery from COVID-19, it seems that having healthy levels from the start could be one of the ways of protecting ourselves from the disease in the first place.

“Evidence shows that having sufficient vitamin D levels helps to prevent and regulate the pro-inflammatory chemicals called cytokines and interleukins that are released when a virus enters the body”, says Dr Joel McCay, Melio’s haematology expert. “Vitamin D also helps up-regulate the T cells and T regulatory cells that help prevent autoimmune disease and remove viral intruders in the body, and early research may suggest that T cells provide longer lasting immunity than an antibody response in those who have had COVID-19.”

How to find out your own vitamin D levels

It’s one thing to want to improve your vitamin D levels, but first you need to know what they are.

“A lot of people take a vitamin D supplement but are not routinely tested to see if it’s enough for them”, says Joel, “and it’s often not that straightforward to get a test. For many people, it takes having something like a stress fracture or signs of osteoarthritis before they get referred for a vitamin D test, which is a bit like closing the gate after the horse has bolted.”

“A simple blood test will tell you your baseline result and help you and your healthcare provider work out the necessary supplementation levels”, says Kush. “As a general rule, results showing less than 30nm/litre mean you are deficient, 30-50nm/litre is insufficient, and above 50 is sufficient and considered the treatment goal when you are supplementing.”

As we head into winter, there’s no time like the present to find out what your vitamin D status is, so you can take steps to address any issues ahead of cold and flu season – which this year has the added layer of risk from COVID-19 as well. Right now, Melio has bundled our COVID-19 antibody test bundled with a free vitamin D test so not only can you find out if you may have had COVID-19, but check your vitamin D level at the same time.

Along with the result of your Melio COVID-19 antibody, you’ll also get a personalised report from Melio’s doctors with advice about how to boost your own vitamin D status to healthy levels through diet and supplementation.

There are many different brands and formulations of vitamin D supplements available, often combined with other supplements (such as calcium), with different dosing regimens, and your pharmacist or GP can advise you about which is best for you: (

Check your Vitamin D levels and Covid-19 antibody status today

If you think you have had Covid-19 would like to know if you have antibodies, you can book a fast and accurate antibody test at one of our growing number of convenient locations today, and find out your vitamin D status at the same time.

We use the Siemens Atellica IM COV2T total antibody blood test, which will be carried out by one of our specially trained health professionals, and includes a free Vitamin D test for just £ 99. Order and pay for your test online, book an appointment at a time and place that suits you, and receive the results directly to your mobile within 24-48 hours. All test results are individually checked by one of our in-house doctors and sent directly to you with a personal medical report which includes any further advice and signposting you may need.

Click here to book your Covid-19 antibody test:, or use the chat button if you’d like talk to one of our specially trained advisors for more information.

You can read more about the role of vitamin D in the body here: and listen to our latest podcast episode on vitamin D and COVID-19 here:


Related products

Related articles