The British Government has ordered an urgent investigation into whether vitamin D can protect people from severe Covid-19.
Scraps of research have emerged suggesting that the ‘sunshine nutrient’ can boost the immune system in a way that helps it fight off the coronavirus but evidence has so far been inconclusive.
Higher rates of Covid-19 death among black and Asian people — who are slower to produce vitamin D from sunlight than white people — have led scientists to think the vitamin could play a role.
Government advisory group the Scientific Advisory Committee on Nutrition (SACN) will review the scientific studies available on the subject to see if there is any truth to the link.
And the NHS regulator, the National Institute for Health and Care Excellence (NICE) will carry out its own review along with Public Health England, it emerged today.
Both reports are expected in the next couple of weeks, The Guardian reports, and could encourage doctors to give coronavirus patients extra vitamin D supplements.
The NHS already recommends people take a supplement because many are missing out on time outdoors while they’re working at home in lockdown. The main source of vitamin D is sunlight.
The health service says there is currently ‘not enough evidence’ to support the claim that vitamin D could protect people from the virus.
The main source of vitamin D for most people is daylight – the body can make its own supply of the nutrient when the skin is exposed to UV rays (stock image)
Vitamin D helps to regulate calcium and phosphate levels in the body, which are crucial for health bones, teeth and muscles.
People need about 10 micrograms of vitamin D every day, which most will get from a relatively short period (less than an hour in bright weather) spent outside.
During spring and summer people get most of the vitamin D they need from sunlight – the skin produces the vitamin when exposed to UV rays. It is also found in fish, meat and eggs, as well as foods that have it artificially added, such as some cereals.
People who aren’t white, however, take longer to produce vitamin D from sunlight because higher levels of melanin stop the light from penetrating as well.
Researchers at the University of East Anglia in May produced a correlation graph showing the relationship between levels of vitamin D (bottom, measured in nmol/l) compared to infection numbers of coronavirus. Countries with low vitamin D levels tend to have the highest case rates per million, they found
Data in a Public Health England report showed that the mortality rate – the number of people dying with the coronavirus out of each 100,000 people – was considerably higher for black men than other group. The risk for black women, people of Asian ethnicity, and mixed race people was also higher than for white people of either sex. People with non-white skin are also at a higher risk of vitamin D deficiency because it takes them longer to make it from sunlight
As a result, black and Asian people are more likely to have vitamin D deficiencies.
Scientists have even suggested that this could be one of the reasons there are more Covid-19 deaths in BAME communities than among white people.
Vitamin D may make the immune system stronger, more able to fight off viral infections and less likely to trigger damaging levels of internal swelling, experts say.
Professor Adrian Martineau, an infectious disease expert at Queen Mary University of London told the Guardian: ‘Vitamin D could almost be thought of as a designer drug for helping the body to handle respiratory [lung] infections.
‘It boosts the ability of cells to kill and resist viruses and simultaneously dampens down harmful inflammation, which is one of the big problems with Covid.’
A lack of vitamin D has in the past been linked to susceptibility to viral infections and also linked health conditions such as high blood pressure and diabetes, which are known risk factors for severe Covid-19.
Researchers at the University of East Anglia last month published a study which found a link between low vitamin D levels and high infection and death rates.
They found general trends showing the infection was more widespread in countries where people were found to have lower levels of vitamin D.
Professor Martineau added that he didn’t know of any clinical trials going on to test the role of vitamin D supplements in people who catch the coronavirus.
But the vitamins are known to be safe and the NHS now recommends that everyone take them in supplements.
It says on its website: ‘Coronavirus update: Consider taking 10 micrograms of vitamin D a day to keep your bones and muscles healthy.
‘This is because you may not be getting enough vitamin D from sunlight if you’re indoors most of the day.
‘There have been some news reports about vitamin D reducing the risk of coronavirus. However, there is currently not enough evidence to support this.’
The health service says black and South Asian people ‘should consider’ taking supplements year-round because they’re at a higher risk of deficiency.
And it encourages everyone to take the supplements during the winter when daylight hours are short and dim.
Scientists say the role of vitamin D definitely warrants further investigation, especially in light of data showing non-white people are at higher risk of death.
Professor William Henley, a medical statistics expert at the University of Exeter said this month: ‘Some of the increased risk suffered by ethnic minority groups cannot be explained by known factors and vitamin D may play a role in explaining this increased susceptibility.
‘There is an urgent need for more research to explore whether vitamin D plays a causal role in protecting against severe COVID-19 infections.
‘We don’t have definitive answers on this yet. But it could potentially be an explanatory factor [for BAME risk].’