Vitamin D, a safe and cheap prophylaxis for Covid-19

As it increasingly appears that the coronavirus epidemic will not leave us any time soon, the news that an effective vaccine may be years away does not go down well on communities forced into isolation, enduring curfews and often economic hardship.

 

In addition to the obvious economic impact, there are also multiple underreported negative side effects of the lockdown, one of which is mental health. For example, the UK charity SANE reported a 200% increase in callers to its mental health helpline in May of this year. In the US, calls to the National Helpline jumped almost 900% in March compared to the same period in 2019. In the state of Victoria in Australia, where Covid-19 cases are surging, recent weeks saw a 33% increase in self-harm patients presented to hospital, as compared to the same time last year.

 

In the list of apparent reasons why one might feel anxious and depressed, the lack of control and feeling of vulnerability surely must contribute. In this battle for survival, we should be exploring anything that would give us the edge.

 

It is somewhat strange therefore that the authorities have not been encouraging people to take vitamin D supplements.

 

While usually associated with bone and muscle health, vitamin D actually refers to a group of steroids that have an array of functions in multiple organs, including the brain and the lungs.

 

Vitamin D is made by the skin upon UVB excitation, with very few foods being a good source of vitamin D.

 

The National Institute for Health and Care Excellence (NICE) and the Royal Society have both recently examined peer-reviewed studies that investigated vitamin D, correlating blood levels with rates and severity of coronavirus in patients. The studies, including data from over 20 countries, found that deficient vitamin D levels in coronavirus patients are correlated with higher mortality rates. One study also report that coronavirus outbreaks in regions of the world with less sunshine are more deadly than more tropical areas.

 

A July study from Israel that wasn’t published in time to be included in the reviews above, examined vitamin D levels in 14,000 people who were tested for Covid-19. The researchers reported significantly lower vitamin D levels in those who were Covid-19 positive compared to those who were negative for the virus. Low blood vitamin D level in those with the virus was also associated with increased likelihood of hospitalisation, after controlling for factors such as demographic, psychiatric and other variables.

 

While correlation is not causation, more data are surfacing that support this link. Excitingly, a recent study from Singapore used human cell models to demonstrate that calcitriol, an active form of vitamin D, inhibited SARS-CoV-2, the virus that causes Covid-19. This is significant as it shows that vitamin D might not only have preventative effects, but may suppress symptom severity by lessening viral reproduction in patients already infected.

 

These studies did not hone in on vitamin D without reason. Even at the very early stages of the coronavirus, experts have pointed out that vitamin D acts on the ACE-2 receptors in the lungs, which is the same receptor that the SARS-CoV-2 virus enters the cells by. It has also long been known that vitamin D has anti-inflammatory effects, which may combat the cytokine storm observed in severe coronavirus patients.

 

Other evidence reinforces the link between low vitamin D and more severe coronavirus symptoms. For example, an astonishing 94% of doctors who have died from coronavirus in the UK are black, Asian or other ethnic minority. The sample all being doctors reduces the likelihood of vastly different socioeconomic status, health knowledge and access to medical treatments. So unlike those who try to use this sad statistic as a political battery ram to propagate the idea of ‘systemic racism’, it more likely suggests that those doctors with darker skin tones (who are less able to produce vitamin D in the northern latitudes and inclement weather of the UK), are more likely to suffer from vitamin D deficiency and are therefore more susceptible to the fatal effects of the virus.

 

And yet NICE concluded their review by advising: ‘There is no evidence to support taking vitamin D supplements to specifically prevent or treat Covid‑19. However, 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.’

 

One might remind NICE of the old adage ‘don’t make the best enemy of the good.’ No one is suggesting that vitamin D can ‘specifically prevent or treat Covid-19’, but the evidence suggests that healthy amounts may well help reduce the severity of symptoms and reduce the number of fatalities.

 

In fact, as the NICE advisory noted, the NHS already recommends most people to take supplementary vitamin D, especially during autumn and winter. This is because a large proportion of people is vitamin D deficient.

 

A study in the UK found a third of those examined had deficient vitamin D levels, with higher rates in the black and Asian populations. A 2011 study found that 41.6% of adults in the US are vitamin D deficient, with the highest rates in the black (82.1%) and the Hispanic peoples (69.2%). Even in sunny Australia, the Department of Health reported that more than a third of adults had deficient vitamin D levels in the winter months, and the populations most affected are minorities with dark skin tones from Asia, Africa and the Middle East. Older people are also more likely to be deficient as the ability to make vitamin D decreases with age. The old and ethnic minorities are also more vulnerable to the coronavirus.

 

So why not encourage the taking of vitamin D supplements? It is cheap, safe and needed by a large proportion of the population even regardless of the pandemic. This is especially true as many cities around the world still discourages people to go outdoors. The UVB required to induce vitamin D production by the skin cannot pass through window glass, meaning that vitamin D deficiency is likely to increase during the lockdowns.

 

Besides any direct potential benefits for the coronavirus, vitamin D supplementation may lead to better cardiovascular health, which is a risk factor for coronavirus fatality, and, importantly for these trying times, improved mental health (low vitamin D is correlated with higher rates of depression).

 

Indeed, an August commentary in Lancet by UK experts who study vitamin D has come to the same conclusion, that “it would seem uncontroversial to enthusiastically promote efforts to achieve reference nutrient intakes of vitamin D, […] there is nothing to lose from their implementation, and potentially much to gain.”

 

As winter begins for much of the world, with coronavirus cases on the rebound in many countries, vitamin D supplementation may be more necessary than ever.

 

In the most trying time in recent memory, vitamin D might be a healthy, safe and affordable supplement that will bring benefits to millions across the board.