BAME people may face a higher risk of dying from the coronavirus because they are more likely to have a vitamin D deficiency, scientists claim.
The pandemic is seeing higher rates of people from black, Asian and minority ethnic backgrounds dying if they catch the coronavirus.
The reasons are still unknown and will likely be numerous and complicated. But some experts think a lack of vitamin D may play a role.
People with darker skin need to spend more time in sunlight in order to get the same amount of vitamin D as a person with lighter skin.
For this reason, the NHS suggests people with an African, African-Caribbean or south Asian background could benefit from take a daily supplement throughout the year.
Vitamin D may have a protective effect against severe coronavirus by regulating the immune system, and deficiencies of it have been linked to other respiratory viruses.
However, the largest study to investigate the link between BAME, Covid-19 and vitamin D in a UK population found no proof.
Data in the 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. The report warned the rate for the ‘Other’ category was ‘likely to be an overestimate’
William Henley, a professor of medical statistics at University of Exeter, told MailOnline the link is worth exploring.
He said: ‘Preliminary research suggests vitamin D levels may also impact on the risk of people suffering from severe COVID-19 infections.
‘In the UK and northern European latitudes, vitamin D deficiency is a public health concern because ultraviolet B (UVB) radiation is of insufficient intensity for vitamin D synthesis during winter months.
‘This is a particular concern for people with dark skin, such as those of African, African-Caribbean or south Asian origin, who will need to spend longer in the sun to produce the same amount of vitamin D as someone with lighter skin.’
The NHS says: ‘If you have dark skin – for example you have an African, African-Caribbean or south Asian background – you may also not get enough vitamin D from sunlight.’
Everyone over the age of one should get at least 10 micrograms of vitamin D per day, the NHS says – it can be found in oily fish, such as salmon and mackerel, in red meat and in egg yolks.
Short periods of time in the sun around midday can also be enough to get the daily recommended amount – although it is not clear how long this takes.
Studies have found that levels of vitamin D deficiency among dark-skinned ethnic groups in Europe can be more than three times as high as they are in white people.
Government data has shown people from BAME groups are more likely to die from Covid-19 than those who are white.
A report published by Public Health England this week revealed that black people with Covid-19 have died at a rate more than double that of white people. Black women died at a rate of 119 per 100,000 and men 257 per 100,000, while white women’s death rate was 36 per 100,000 and white men’s 70 per 100,000.
For people of Asian ethnicity the rate of death from Covid-19 in England has been 78 per 100,000 for women and 163 per 100,000 for men.
Professor Henley said: ‘This can be partly explained because people from ethnic minorities suffer from a number of social and economic disadvantages.
‘However, 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].’
A lack of vitamin D has been linked to susceptibility to pick up viral infections and has previously been correlated to underlying health conditions such as high blood pressure and diabetes, which are known risk factors for COVID-19.
Researchers at the University of East Anglia recently published a study which found a link between low vitamin D levels and high infection and death rates.
In some hot countries, including Italy and Spain, intake of the vitamin is low and the virus is rife, despite an abundance of sunshine.
Researchers say this is partly because residents in southern Europe have darker skin pigmentation, which reduces the body’s ability to produce natural vitamin D.
The highest average levels of vitamin D are found in northern Europe, where there is higher consumption of cod liver oil and vitamin D supplements, the researchers say.
One researcher suggested the pandemic could be curbed by addressing vitamin D deficiencies in European countries where there are more darker skinned people.
Writing in the British Medical Journal in April, researcher Robert Brown, of the McCarrison Society in Jersey, said: ‘Northerly resident; Europeans with darker skins; BAME, and African Americans; as well as more southerly elderly Spanish and Italians; are often vitamin D deficient.
‘IF, vitamin D deficiency, increases the risk of COVID-19 related; infection, hospitalisation and mortality; one would expect, and indeed sees, higher COVID-19 hospitalisation and mortality, in; dark-skinned northerly residents.’
Vitamin D helps boost the immune system’s innate response. But it also reigns it in when necessary.
Therefore a deficiency could exacerbate an exaggerated immune response.
A common issue for patients diagnosed with COVID-19 is their immune system responds aggressively as it tries to defeat the invading pathogen.
This can lead to an enormous immune response and trigger a dangerous ‘cytokine storm’, which can lead to respiratory failure and multi-organ failure.
It plays a major role in the death in many COVID-19 patients and has become a focus for where to target treatment.
The largest study to properly investigate whether vitamin D deficiency had a part to play in BAME Covid-19 deaths found no evidence this was the case.
Naveed Sattar, a professor of metabolic medicine at University of Glasgow, led the research which studied levels of 25-hydroxyvitamin D in 449 people’s blood. This was a measure of deficiency.
They found that there appeared to be a link between deficiency and the likelihood of having severe Covid-19 but this disappeared when other factors, such as linked illnesses, were taken into account.
The researchers concluded: ‘Our findings do not support a potential link between vitamin D concentrations and risk of COVID-19 infection, nor that vitamin D concentration may explain ethnic differences in COVID-19 infection.’
Professor Sattar had previously slammed the ‘overstretched findings’ of a study which said vitamin D deficiency was a risk factor for Covid-19 death in men.
Researchers in Brussels Free University compared vitamin D levels in almost 200 COVID-19 patients with more than 2,000 healthy people.
Men who were hospitalised with the infection were significantly more likely to have a vitamin D deficiency than healthy men of the same age.
Deficiency rates were 67 per cent in the COVID-19 patient group, and 49 per cent in the control group. The same was not found for women.
Professor Sattar said: ‘I must say the vitamin D paper is potentially critically flawed. This is because blood vitamin D levels go down when people develop serious illness.
‘This means that it is likely the occurrence of illness that is leading to lower blood vitamin D levels in this study, and not that low vitamin D levels are causing COVID-19.
‘Hence, I think the authors have massively overstretched their conclusions.’
Carolyn Greig, professor of musculoskeletal ageing and health, University of Birmingham, said: ‘At present there is still insufficient evidence for vitamin D as a treatment for COVID-19.’