‘Extremely foolish’ not to urge vitamin D supplementation for all, says scientist
After research published in Scientific Reports showed an “impressive linear correlation” between European countries’ latitude and the date of their autumn Covid surge, and pointed to vitamin D levels as a contributory factor, there are calls to rapidly address deficiencies of the sunshine nutrient across the continent.
Jon Rhodes, an emeritus professor of medicine at the University of Liverpool, said:
This study confirms previous reports showing associations between Covid-19 risk and latitude and this fits with its evident seasonality. The risk of dying from Covid-19 correlates with ethnicity, obesity, and also with lack of sunlight /ultraviolet exposure - whether as a consequence of latitude, season, or by being institutionalised. All these factors are strongly associated with vitamin D deficiency.
Vitamin D deficiency impairs immune function and a recent study has shown this can be readily corrected by daily supplementation. Doctors, many of whom take vitamin D supplements themselves, know that placebo-controlled interventional trials are not the only form of useful scientific evidence – smoking and lung cancer being a classic example.
We know about half the UK population are likely to be vitamin D deficient. It is extremely foolish not to urge daily vitamin D supplementation for everyone during the pandemic - it is very cheap and safe, at worst will do no harm, and at best might be lifesaving for many.
The study’s author, Stephan Walrand, from Cliniques Universitaires, the largest hospital in Brussels, Belgium, wrote in the peer-reviewed paper:
As already evidenced by previous correlation studies, a low [vitamin D] concentration should be considered a contributing factor to Covid-19 severity. Europe and the northern USA are starting a long Covid-19 crisis this autumn, as they will return to a level above the October sun UV daily dose only at the end of March 2021. Measures to reduce the pandemic severity during the coming winter using controlled preventive vitamin D supplementation should be considered.
A graph from the study shows no correlation between temperature or humidity and Covid surge dates, but a stark relationship with latitude. Photograph: Scientific Reports
Research suggesting a link between low vitamin D levels and the worst Covid outcomes is growing. There are many dozens of observational studies from around the world that make such indications, along with a randomised control trial (RCT) from Andalusia, Spain.
In the study, conducted in early September, 50 patients with Covid-19 were given a high dose of vitamin D, while another 26 patients did not receive the nutrient. Half of patients who weren’t given vitamin D had to be placed in intensive care, and two later died. Only one patient who received vitamin D required ICU admission, and they were later released with no further complications.
The researchers are now doing a much larger trial across a number of hospitals. Meanwhile, results are expected in the coming weeks from a large French trial that was reportedly named a “national research priority” by the French government in December.
An RCT with 6,200 patients was launched in the UK with charitable funding in October to examine whether vitamin D supplementation reduces the risk and severity of Covid-19 and other acute respiratory infections.