The idea that vitamin D supplements can reduce the susceptibility and severity of Covid-19 is seductive – it offers a simple and elegant solution to a very complex and deadly problem. But analyzes spanning large European data sets suggest that enthusiasm for the sunshine vitamin may be misplaced.
Two articles that have not yet been peer-reviewed analyzed the link between vitamin D levels and Covid-19 and both came to the same conclusion: evidence of a direct link between vitamin D deficiency and Covid results is lacking. .
A group of researchers mined a database out of hundreds of thousands of mostly white participants to understand whether giving them vitamin D could lower their chance of having severe or symptomatic Covid.
The researchers analyzed the records of people with certain genetic markers that predispose them to vitamin D deficiencies, something that is not influenced by factors such as age and other underlying conditions. They found no evidence for the idea that supplements protect against Covid.
Other study compared the prevalence of vitamin D deficiency in 24 European countries with Covid infections, recovery, and mortality data.
Lead author Dr. Michael Chourdakis, University of Aristotle, Greece, said the analysis avoided the methodological limitations of previous studies by using only recent data on vitamin D and not only included subsets of the population, for example, people in nursing homes.
Also, instead of using average vitamin D levels, which can be distorted by certain parts of a population that have very high or very low concentrations, they specifically looked at deficiency levels.
“There is an information overload on the benefits of vitamin D … vitamin D has been praised for too many things,” he said, “although we have very limited data on that.”
He added that the study was methodologically robust and the data does not show a significant correlation between vitamin D and Covid infections, recovery, or mortality.
Those who traditionally exhibit vitamin D deficiency (older adults and ethnic minority populations) are the same groups that have been disproportionately affected by Covid-19. Prolonged blockages and shielding of subsets of the population have also improved the time spent indoors away from sunlight rich in vitamin D. And, in general, vitamin D has been implicated in helping the immune response to respiratory infections, which is why supplements seem like the intuitive answer.
But the evidence on Covid so far, though some of this is positive – is circumstantial. Some researchers argue that it is not robust enough favor a population-wide supplementation policy, particularly given the impact it could have on individual behavior and the potential negative physical side effects of taking too much.
In a recent review, the National Institute for Excellence in Health and Care (Nice) agreed, evidence of vitamin D supplementation with the aim of preventing or treating Covid was yet to be found and more research was needed.
“We are scientists, we believe in data. We believe that today’s data suggests that vitamin D will not protect against Covid results. We would be happy to consider any data that suggests otherwise, ”said Dr. Brent Richards, a clinical scientist at McGill University specializing in endocrinology, epidemiology and biostatistics, one of the authors of the genetic study.
“But it is important to remember that in the field of vitamin studies there is a general public familiarity with vitamins and a high level of trust that we do not see with other types of interventions. So people really want this solution to be a vitamin-based solution, and sometimes that’s not always the case. “
A recent example is a study by scientists at the University of Barcelona that suggested that giving high doses of vitamin D to coronavirus patients when they are admitted to hospital could reduce deaths by a staggering 60%, prompting calls from the former Brexit secretary and MP David Davis for the therapy to be implemented in hospitals.
But some scientists he pointed that although the data is presented as a randomized trial of vitamin D supplementation, it appears that individuals were not randomized, but hospital wards. Different wards tend to accommodate different patients depending on their level of disease and risk.
Finally, the study, which had not been peer-reviewed, was remote from The Lancet medical journal server as a result of concerns that prompted an investigation into the newspaper.
in the meantime randomized controlled trials designed to definitively answer whether vitamin D status plays a direct role in Covid infections and the results are in progress. “What we are missing at the moment is really a definitive trial that demonstrates a cause and effect relationship,” said Adrian Martineau, professor of respiratory infections and immunity at Queen Mary University of London, who is leading the study.
“You cannot rule out circumstantial evidence …[but] it is not the highest level of evidence. I suppose there is a philosophical question: if you have an intervention that has a good chance of working and is completely safe, why not implement it while you wait to find out given the public health emergency?
George is Digismak’s reported cum editor with 13 years of experience in Journalism