A preliminary study has found tentative evidence suggesting low levels of vitamin D may make it more likely an individual will die after contracting coronavirus.
The research compared average levels of vitamin D across 20 European countries with COVID-19 infection rate and mortality.
It revealed a convincing correlation where countries with low vitamin D levels were also the countries with highest mortality and COVID-19 infection rates.
The study has not yet been peer-reviewed and scrutinised by other scientists and is unable to prove vitamin D is the reason behind this link.
However, the scientists from Queen Elizabeth Hospital Foundation Trust and the University of East Anglia write in their study:
“We believe, that we can advise Vitamin D supplementation to protect against SARS-CoV2 infection.”
This finding backs up a separate study which also found vitamin D may improve a person’s chance of recovery after contracting the coronavirus.
A ten-week trial from the University of Granada is currently ongoing after a recent study by Trinity College Dublin found adults who took Vitamin D supplements saw a 50 per cent fall in chest infections.
The latest study used pre-existing data on vitamin D levels, including from a comprehensive 2019 study led by Paul Lips, Professor Emeritus of internal medicine at Vrije Universiteit Amsterdam.
This previous study collected data on vitamin D levels of populations across Europe and the Middle East.
The study involved taking vitamin D measurements of thousands of individuals.
The latest study on the vitamin’s effectiveness against COVID-19 narrowed this data to 20 countries, to negate any interfering factors, such as a country’s latitude.
The average amount of vitamin D in serum samples was (56 nmol/l), with anything below 30nmol/l deemed ‘severely deficient’.
The latest study took the existing database of vitamin D levels and found worryingly low levels of vitamin D in the elderly, a demographic more at risk of dying after contracting the coronavirus.
“[The study shows levels of] vitamin D of 26nmol/L in Spain, 28 nmol/L in Italy and 45 nmol/L in the Nordic countries, in older people,’ the researchers write.
“In Switzerland, mean vitamin D levels are 23(nmol/L) in nursing homes and in Italy 76 per cent of women over 70 years of age have been found to have circulating levels below 30nmol/L.
“These are countries with high number of cases of COVID–19 and the ageing people is the group with the highest risk for morbidity and mortality with SARS-Cov2.”
Vitamin D can make its way into the human body either through certain foods, such as fish and mushroom, or can be produced by skin cells when exposed to sunlight.
A simple statistical analysis, called a t-test, was then performed on the two sets of data to determine any relationship which unearthed the correlation between deaths and vitamin D levels.
“The most vulnerable group of population for COVID-19 is also the one that was the most deficit in vitamin D,” the researchers conclude in their preliminary report.
The study was published on pre-print site Research Square.
It remains unknown why vitamin D may offer protection against infection by the coronavirus SARS-CoV-2 and the subsequent development of COVID-19.
However, the study is backed up by previous research that was published before the emergence of the novel coronavirus.
Healthy vitamin D levels have been linked to reduced risk of other respiratory diseases, such as influenza, tuberculosis and childhood asthma.
Recently, skin cancer researcher Dr Rachel Neale said that having low levels of vitamin D can be fatal if one also has the coronavirus.
“It would make sense that being vitamin D deficient would increase the risk of having symptomatic COVID-19 and potentially having worse symptoms. And that’s because vitamin D seems to have important effects on the immune system.”
Last year, Dr Neale found that people with low levels of vitamin D are almost twice as likely as those with high levels of vitamin D oto develop acute respiratory infections.
According to the study of 78,000 patients, people with vitamin D deficiencies were more likely to be sicker for longer.
Dr Neale said she sits in the Brisbane sun for for five to 10 minutes everyday to stimulate her body’s production of vitamin D.
Trinity College Dublin published research last month which found vitamin D may be able to help reduce the severity of COVID-19.
The Irish team found the vitamin is likely involved with suppressing the severe inflammatory responses seen in seriously ill COVID-19 patients.
Professor Rose Anne Kenny, who led this research, said:
“We have evidence to support a role for Vitamin D in the prevention of chest infections, particularly in older adults who have low levels.
“In one study Vitamin D reduced the risk of chest infections to half in people who took supplements.
“Though we do not know specifically of the role of Vitamin D in COVID infections, given its wider implications for improving immune responses and clear evidence for bone and muscle health, those cocooning and other at-risk cohorts should ensure they have an adequate intake of Vitamin D.
“Cocooning is a necessity but will reduce physical activity. Muscle deconditioning occurs rapidly in these circumstances and Vitamin D will help to maintain muscle health and strength in the current crisis.””
How vitamin D deficiency can affect the human body
Vitamin D deficiency – when the level of vitamin D in your body is too low – can cause your bones to become thin, brittle or misshapen.
Vitamin D also appears to play a role in insulin resistance, high blood pressure and immune function – and this relates to heart disease and cancer – but this is still being investigated.
Low levels of the vitamin have also long been linked to an increased risk of multiple sclerosis.
Although the amount of vitamin D adults get from their diets is often less than what’s recommended, exposure to sunlight can make up for the difference.
For most adults, vitamin D deficiency is not a concern.
However, some groups – particularly people who are obese, who have dark skin and who are older than age 65 – may have lower levels of vitamin D due to their diets, little sun exposure or other factors. (Source)