Does vitamin D protect against COVID-19?

Social media currently abounds with ‘useful’ information about medication and supplements that will protect you against COVID-19. Much of this is hearsay and downright wishful thinking. Prime example is President Trump taking hydroxychloroquine as preventative medicine. I hope he does not come into any mischief as have so many in recent studies.

How about vitamin D?

Interest in vitamin D is has been sparked via two main channels. First of all, people are now looking with interest at a meta-analysis (good quality evidence) published in the British Medical Journal in 2017. This included 25 studies with a total of over 11,000 participants. It showed that vitamin D supplements were safe and that they protected against respiratory infections. COVID-19 causes respiratory symptoms and hence the increased interest in this study nowadays.

The second observation is that people from black, Asian, and minority ethnic (BAME) backgrounds have a greater rate of COVID-19 infection and death rate compared to white Caucasians. People from ethnic backgrounds represent 14% of the UK population but 34% of COVID-19 patients. Death rate in British Black Africans and British Pakistanis is 2.5 times that of the white population. If we look at NHS staff, then those from BAME backgrounds represent 64% of deaths despite only making up 20% of the NHS workforce. Among doctors, the death rate in Blacks and Asians is an astounding 94% of the total number.

These inequalities in COVID-19 infection and death rate have been thought to be due to greater health problems in ethnic minorities. There is also an increased incidence of poverty, and they tend to live in larger, extended families. However, that does not entirely explain the disparity in rates of death among doctors. This is why vitamin D levels have become so interesting.

Researchers from the United States have found that patients from countries with high death rates such as Italy, Spain and the UK, had lower vitamin D levels than those not so severely affected. Another study also showed that average vitamin D levels in countries were strongly related to COVID-19 cases and death rate.

What does NICE say?

As always the National Institute of Health and Clinical Excellence prefers to side with hard evidence. In December 2020 they came out with rapid guidance advising people in the UK to continue to supplement with vitamin D in the Autumn and Winter months. However, they also said that there was not currently enough evidence to support taking vitamin D solely for the prevention and treatment of COVID-19.

The problem with this guidance is that we do not have the luxury of waiting until all the evidence is collected. People continue to suffer severe COVID-19 infections, become hospitalised, die or have prolonged suffering from long-COVID. We should be acting on the evidence we have so far even if it is not the gold standard randomised controlled trials. Vitamin D is cheap, has no adverse effects in standard doses and is good for bone health. There is little or no harm from taking it and potentially great benefit.

What’s the verdict?

My opinion is that we should all be taking vitamin D supplements based on the evidence we have so far. This is especially important for high risk groups such as those with BAME backgrounds and key workers. Standard doses for adults of 1000 IU are available over the counter, and higher doses of 4000 IU are available online. Since I have multiple risk factors for severe COVID-19 including being a doctor with an Asian background, I am taking the higher dose of 4000 IU per day.

Taking vitamin D supplements does NOT mean that we should avoid taking the COVID-19 vaccine. We should also continue to follow standard advice regarding hand hygiene, face coverings and social distancing,

The results of further studies on COVID-19 and the role of vitamin D should be released later this year. These should make matters clearer once and for all. Until then, I would err on the side of caution and take supplements.