A “simple, safe and inexpensive” measure, this is how 73 French-speaking experts and six national learned societies * qualify vitamin D supplementation as part of the fight against the Covid-19 epidemic. In a jointly published article, they call for supplementing the French population as a whole with vitamin D, and not only the elderly or at risk of severe infection. Recently posted in The practitioner’s review, the latter specifies all the scientific data currently available on vitamin D and COVID-19 and underlines the importance of ensuring a satisfactory vitamin D status for the entire general population.
These experts gathered around Professor Cédric Annweiler, head of the geriatrics department at Angers University Hospital, recall that a growing number of scientific studies show that the vitamin D supplementation could contribute to reduce infection with SARSCoV-2 as well as the risk of severe forms of COVID-19, resuscitation and death. But they are clear on one point: it should not be considered a weapon of the same level as vaccination or barrier gestures. The interest of this measure would be to maintain satisfactory vitamin D status in the general population, including healthy people of all ages, in the context of COVID-19.
When is supplementation required?
Their authors formulate this request “given the high frequency vitamin D deficiencies (hypovitaminosis) found in 40 to 50% of the French population and more in people at risk of severe forms of COVID-19, given the many scientific arguments in favor of a beneficial effect of this supplementation (and while awaiting the results of large-scale clinical trials in progress), and given the absence of risks associated with vitamin D supplementation at appropriate doses. “According to them, supplementation before any infection with SARS-CoV-2 on a large scale would ensure that as few people as possible have hypovitaminosis D.
A request which is more similar to that published by the Academy of Medicine last May. The argument of experts in this direction concerns the fact that certain categories of the population at risk of hypovitaminosis D already benefit from supplementation year round (obese, elderly, sick people), while the general population can be supplemented during the winter when its production in the skin is almost zero. Indeed, vitamin D, whose main function is to increase the concentrations of calcium and phosphorus in the blood, is synthesized in the dermis under the effect of the sun’s rays then transported to the liver and kidney where it is transformed into an active hormone.
The authors believe that “it actually amounts to following the many national and international recommendations (before the COVID-19 epidemic) to ensure a satisfactory status in vitamin D in everyone, and there is no need to wait for the results of new studies dedicated to COVID-19. ” But what about a proven infection with SARS-CoV-2? If the impact on prevention and / or improvement of severe forms of COVID-19 is still the subject of studies, they recommend to obtain as quickly as possible a satisfactory status in vitamin D thanks to a supplementation at high dose, and this as of the diagnosis made and without waiting for the result of the dosage of the vitamin.
Be careful, however, supplementation must be prescribed by a doctor because there is a risk of intoxication, although rare, generally linked to self-medication. The article of The practitioner’s review indicates that meta-analyzes had previously reported a protective effect of vitamin D supplementation on acute respiratory tract infections since it is also involved in the differentiation and activity of cells of the immune system. Regarding Covid-19, it would make it possible to modulate the expression of ACE2, considered an “entry point” because used by SARS-CoV-2 to infect host cells.
A clinical trial conducted in France with elderly people
However, ACE2 has protective effects against inflammation in several organs including the lungs. “The negative regulation of ACE2 by SARSCoV-2 causes an inflammatory chain reaction (cytokine storm) which can be complicated by an acute respiratory distress syndrome with a risk of death ”, explain the authors. Supplementation would also be necessary because hypovitaminosis D seems to constitute a risk factor for severe form of COVID-19. “This point is interesting because, unlike other risk factors of severe form, hypovitaminosis D is a risk factor easily modifiable by drug supplementation”, note the authors.
A clinical trial called COVIT-TRIAL promoted by the Angers University Hospital is testing the effect a high dose of vitamin D administered upon diagnosis of COVID-19 compared to a standard dose on the risk of death from COVID-19 in frail elderly people who have contracted the infection. Ten French hospitals and their EHPADs are participating and the results will clarify the value of a high dose of vitamin D in patients. Internationally, learned societies have already published opinions recommending vitamin D supplementation in the context of the epidemic. The British government would have even planned to provide vitamin D as a preventive measure to several million fragile people.
* The French Association for the Fight against Rheumatism (AFLAR), the French Society of Endocrinology (SFE), the French Society of Geriatrics and Gerontology (SFGG), the French Society of Pediatrics (SFP), the French Society of Endocrinology and Diabetology pediatric (SFEDP), the Francophone Society of Nephrology, Dialysis and Transplantation (SFNDT)
To find out more about the coronavirus, the editorial staff invites you to discover its more complete and regularly updated articles:
- an article on Covid-19 disease and the evolution of the epidemic
- an article on the different screening tests
- an article on vaccines under development.