At a time when any question about a potential treatment for Covid-19 is very sensitive, this publication is obviously making a lot of noise.
This Tuesday, 73 doctors and six associations of doctors called "to supplement the whole of the French population with vitamin D" in a preventive way, to fight in particular against the serious forms of the infection.
Beware of announcement effects, temper specialists.
Written by 73 French-speaking "experts", and supported by six national learned societies, such as the French societies of endocrinology, pediatrics and geriatrics and gerontology, this forum recommends "supplementing the entire French population with vitamin D" .
It follows a so-called “consensus” article published on January 8 in the Practitioner Review.
The latter lists a number of studies on the usefulness of vitamin D in the context of Covid-19 infection.
Known for its role on the immune system
According to figures put forward by the authors, 40% to 50% of the French population is deficient in vitamin D, "and even more in people at risk of severe forms of Covid-19".
Without wanting to replace vaccination, they therefore recommend "a high dose vitamin D supplementation" as soon as the diagnosis of Covid-19, to "obtain as quickly as possible a satisfactory status in vitamin D".
Well known, vitamin D plays a role in the immune system, and is used in the development and maintenance of bones.
Found in food, it is mainly synthesized in the body under the action of sunlight.
Its natural production is "almost zero at French latitudes" during the winter period.
If these different points are consensus in the scientific community "we know nothing at all about the use of vitamin D in the treatment of infectious diseases, it has just come out", is surprised Jean-Paul Stahl, professor emeritus of infectiology at the University of Grenoble.
“We turn to old stuff.
We have the choice, we sometimes bring out vitamin A, C or D. It's easy, it looks pretty, it feels organic, ”he quipped.
"Observational" studies
Concretely, according to the authors of the forum, which are based on a long list of studies and recommendations, vitamin D influences the action of many genes.
In particular, it regulates the production of an enzyme present on the membrane of cells (ACE2), which constitutes the entry point of the coronavirus into cells.
What credit should be given to this work?
“These are observational studies, curve observations.
There is no randomized, normal study, as with a normal drug, ”recalls Jean-Paul Stahl.
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"Attention correlation does not mean causality," warned infectious disease specialist Karine Lacombe on BFMTV this Wednesday morning.
"People with third-party infections or severe forms of Covid more often have a vitamin D deficiency. But the converse is not true", points out Eric Billy, researcher in immuno-oncology.
“The healthier you are, the better your general condition, the more you eat well, the less risk you will have,” adds Jean-Paul Stahl.
If it doesn't do good, it won't hurt.
But what is certain is that it will not work a miracle ”.
Pr Karine Lacombe: "Vitamin D is not an effective means of preventing Covid-19" pic.twitter.com/Eerl7VDapr
- BFMTV (@BFMTV) January 20, 2021
Large-scale clinical trials carried out in Angers
According to Le Monde, the High Authority for Health ensures that no recommendation is considered for the moment, “since no solid study makes a link between the intake of vitamin D - delivered only on prescription - and the reduction of symptoms of Covid-19, ”the newspaper reports.
She nevertheless says she is monitoring this work "with attention".
“Large-scale” clinical trials are also underway, including one coordinated by the Angers University Hospital.
The results of this research, classified as a "national priority", will be known in the coming weeks and "will make it possible to clarify the interest of a very high dose of vitamin D in patients with COVID-19", according to the establishment.
“You shouldn't be obtuse, why not look at the effects of vitamin D, but you have to demonstrate it before prescribing.
The fashion is with calls, various and varied, and the problem of this kind of thing is that it throws a disorder in the public order ”, recalls Jean-Paul Stahl, while the specter of the debate on hydroxychloroquine hovers still above all heads.