In the midst of the COVID-19 pandemic, many studies have suggested the possible association between low serum vitamin D levels and mortality from Covid-19. This vitamin could indeed play a role in the regulation and suppression of the inflammatory cytokine response at the origin of the acute respiratory distress syndrome which characterizes the severe forms of the disease. The interest of the scientific community for this vitamin even led the Academy of Medicine to point out last May in a press release that “vitamin D could be considered as an adjuvant to any form of therapy in mitigating inflammatory storm and its consequences. ”
In a prepublication study, researchers at King’s College London are not only interested in the possible benefits vitamin D supplementation in this context, they analyzed the effect of several types of vitamins. Their analyzes are based on the use of the “ZOE COVID Symptom Study” application used by 1.4 million people in the UK, US and Sweden. “We looked for correlations between taking supplements and reporting a positive COVID-19 test using a PCR or serological test, or having predictive symptoms of COVID ”, Explains Dr. Cristina Menni, lead author of the study.
No effects observed with vitamin C and zinc
The data showed that more than 44,500 users reported a positive COVID-19 PCR or serology test and more than 12,000 had one of the most predictive symptoms of the disease, loss of smell. The results revealed that multivitamin, vitamin D, omega-3 and probiotic supplements all had a very weak but statistically significant protective effect against COVID-19, while the vitamin C, zinc supplements or garlic had no detectable effect. However, when the researchers broke down the analysis by gender, they found that this beneficial link was oddly only present in women.
“We have found that multivitamins, vitamin D, omega-3s and probiotic supplements modestly helped protect women, but we did not see the same consistent protective effect for men. It was a surprising result. Adds Dr. Cristina Menni. The researchers suggest that this finding may be explained by the differences in the immune system between men and women, the latter having even been highlighted in other studies of immune responses. during Covid-19 disease. The other assumption being a “reporting bias”, namely that a sex reported their information more accurately.
Taking care of general health is the most important
According to the researchers, the explanation may also come from a “healthy bias”. Indeed, the people who take vitamins and other supplements would be more likely to take better care of their overall health and better follow measures to avoid catching the infection, such as wearing a mask and washing their hands. This so-called “healthy bias” could therefore explain why people who took supplements were less likely to catch the virus. “However, if the results only reflected the effect of this healthy bias, one would expect that all supplements have a protective effect but this was only observed for a limited range. », They note.
While these results are intriguing, they do point out that more studies need to be done as they do not definitively prove that supplementation can reduce risks of contracting the virus. According to Dr. Cristina Menni, “This is an observational study and not a clinical trial, so we cannot make any solid recommendations based on the data we have. Until we have further evidence on the role of supplements from randomized controlled trials, we recommend that you follow official health guidelines. on the use of vitamins as part of a healthy and balanced diet. ”
Certain herbal food supplements that are not recommended
In France, ANSES warned consumers in April about do not use food supplements containing certain plants at the risk of disrupting the body’s natural defenses, interfering in particular with useful inflammatory defense mechanisms to fight infections, in particular, against COVID-19. These are plants containing salicylic acid derivatives (aspirin analogues) such as willow, the meadowsweet, the birch, poplar, goldenrod, polygalas but also plants containing other plant anti-inflammatory drugs, such asharpagophytum, echinacea, turmeric and cat’s claw (liana of Peru).
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.