Covid19 and Vitamin D

There are many unsubstatiated rumours on the internet about what you can take to keep Covid19 at bay.

I don’t want to add to them, so let me state up-front that I know of no conclusive scientific evidence (in June 2020) that vitamin D by itself can prevent a person from becoming infected with Covid19, or cure a person who has the infection.

That does not mean that vitamin D is of no use against Covid19. There are some indications that it might be extremely helpful, which you might want to consider.

So what is the evidence?

Scientists are becoming interested in vitamin D in relation to Covid19. According to Northwestern University (Illinois)

After studying global data from the novel coronavirus (COVID19) pandemic, researchers have discovered a strong correlation between severe vitamin D deficiency and mortality rates.

Furthermore, the World Health Organisation acknowledges that vitamin D deficiency is associated with several different kinds of respiratory infections in children.

…vitamin D deficiency has been linked to respiratory infections such as pneumonia, tuberculosis and bronchiolitis.

A Science Daily publication reveals that in 2013, the University of Eastern Finland reported that the risk of contracting pneumonia was more than 2.5 times greater in subjects with the lowest vitamin D levels, compared to those with the highest. This was a study of 1421 people.

According to this paper published in 2020 Vitamin D slows down the replication of viruses (inside our bodies) by several means, which helps our immune system get on top of the situation in time to stop the virus from getting the upper hand.

Vitamin D also reduces inflammation and calms the immune system, which may stop it from getting into a frenzy and unleashing a cytokine storm. This overreaction of the immune system is what actually causes most Covid19 deaths.

Circumstantial evidence

I don’t know if anyone is routinely measuring the vitamin D levels of people who are infected with Covid19. I hope they are. But there are substantial indications that vitamin D levels may affect Covid-19 risks.

  • Vitamin D levels are lower in older people (their skin is less efficient at producing it) and we know that older people are also more likely to die from Covid19.
  • Others more likely to die from Covid19 are those with heart disease, respiratory disease, dementia, diabetes and kidney disease. Each of these diseases is also associated with low vitamin D levels.
  • Overweight and obese people are more likely to die from Covid19. Overweight and obese people tend to have lower vitamin D levels.

Different Death Rates for Black People

I live in the UK. There’s a rather odd anomaly in the UK’s Covid19 statistics. In the UK, if you are infected with Covid19, it appears you are more likely to die from the virus if you belong to the group of people known collectively as Black and Minority Ethnic (BAME). The highest Covid19 death rate is among black people.

This is not something peculiar to black people generally, but to black people living in the UK (and no doubt in some other countries too). According to recent WHO statistics, I note that in sunny South Africa (where black people represent 80% of the population) cumulative Covid19 cases (all race groups) was 80412 (on 19th June 2020) and total deaths were 1674 (i.e. one death per 48 people infected).

Whereas in the UK, looking back to the time when they had a similar accumulation of cases (78995 cases on 12th April 2020), a total of 9875 people had died. That is an average of one death for every 8 people infected. (And for black people in the UK, we know the death rate would have been very much higher than average.)

What Causes the Difference?

So why were people so much more likely to die from Covid19 in the UK than in South Africa? Of course, there may be multiple reasons. (One of them could be that the average age in UK is higher than in South Africa.)

But a major reason could be that most people in South Africa get way more sunshine on their skin than do people in the UK, so their vitamin D levels are much higher (even though 80% of the SA population are black).

The difference in death rates between UK and SA would be most noticeable among black people, who get enough sun exposure in South Africa to generate plenty of vitamin D, but who cannot make enough of it in the U.K.

In fact, studies from South Africa – from various regions of the country – show average serum levels of 25(OH)D in children ranging from 56.8 nmol/L to 129 nmol/L. Black adults had lower average levels, but still well above vitamin D deficiency (nominally 50 nmol/L).

Whereas in the UK, 55% of the population is vitamin D deficient. according to this international study – and I would expect this percentage to be significantly higher for black people.

So even though definitive proof is lacking, the evidence is mounting that vitamin D levels may have an effect on Covid19 detected infection rates, and may well have a huge effect on Covid19 survival rates.

My personal opinion is that there may be a large number of people who have had Covid19, but have never been included in any published statistics of Covid19 cases because they never got sick enough to think of getting themselves tested – and that the majority of such people would have had near-optimum blood levels of vitamin D.

So what?

Our scientists and government – and others around the world – should be looking carefully into the vitamin D issue. Hopefully they are – and not just in connection with Covid19.

But it is particularly important now for us all to deal with vitamin D deficiency, which appears to make people more vulnerable to respiratory infections, and more likely to die from Covid19 if they are infected.

Meanwhile, what do we have to lose by making sure that each of us has adequate (or better still, optimum) levels of vitamin D?

And how might it affect the Covid19 pandemic if all of us did this?