From the start of the pandemic, several patients consulted with our pharmacies for advice on this new virus. And as a conscientious pharmacist, at first glance, I knew that traditional pharmacology had very few tools to fight viral infections, whether it is the seasonal flu or HIV for example. In the absence of specific conventional drugs, and even more so, for the over-the-counter drugs that I can recommend without a prescription, it became clear to me that under the circumstances, the best advice was to offer my patients’ recommendations to improve their immune system in general to better resist this unknown infection. It’s common sense.

Certain groups and certain professionals hastened to recommend some traditional medicines (colchicine, chloroquine, hydroxychloroquine for example), although there is no scientific proof that these products could be useful. On the other hand, what surprised me most was that nobody seemed inclined to recommend the use of certain so-called “natural” supplements, because in their case too, nothing “proved” their effectiveness. Two weights, two measures? It was also true for so-called “conventional” drugs, but we tried to use them nonetheless. It is normal in an unprecedented situation to use drugs which we have reason to believe may help combat this new enemy. Trying traditional drugs, okay, but it would have been just as normal to assess what natural supplements might be useful.

In a state of emergency, where many people risk losing their lives, all possibilities should be considered. You have to be open-minded, and try to do an all-round prevention, including the standard hygiene rules recommended by our governments, but also correct known risk factors (smoking, lack of sleep, diet containing too much sugar, etc.), including also recommending the use of certain supplements. I will speak here about several facets which seem to be confirmed for the use of vitamin D and certain minerals, as well as the tests considered in Traditional Chinese Medicine (my past as an acupuncturist catches up with me!), with non-specific antivirals which could therefore broaden the spectrum.


All of the preventive measures we heard about were almost all physical: containment, sneezing in your elbow, 2m distance, masks, etc. Where are the biological preventative measures? Preventive measures based on optimizing health? Certain subjects were discussed on the Vitoli blog in connection with Covid-19, including stress control (Coronavirus and stress : Everything you need to know and Are we victims of COVID? How can we not be?). Stress in particular is one of our worst enemies due to its negative effect on the immune system, and unfortunately, it is omnipresent.

Prevention of course should include eating well, being active, sleeping well and making sure you don’t miss out on certain nutrients like vitamin D, selenium and zinc. I will also introduce you to some plants used in Traditional Chinese Medicine.

Vitamin D

It is the best documented supplement for its impact on the risks of the disease and/or the risk of complications. We know that high levels of vitamin D are associated with a reduction in herpes, hepatitis B and C, HIV, influenza, etc. This is true for several studies from different countries on different continents. There is a correlation between vitamin D levels and the severity of Covid-19 disease in confirmed cases. This means that for people who catch the virus, their level of vitamin D is linked to the level of severity of the symptoms; Vitamin D deficient people have significantly more severe symptoms, which increases the risk of death.

You should know that more than a billion people are deficient in vitamin D, especially in late winter or spring; because few foods contain it and that the main source is the production of our skin in response to sun exposure. Sun and confinement do not mix!

Vitamin D modulates the adaptive and innate responses of our immune system, among other things by reducing the mucosal inflammatory response (which would also partly explain its benefits in the case of Covid-19). 1000 to 5000 IU of vitamin D3 would be recommended per day, but also know that 20 minutes of sun exposure without sunscreen can produce between 10,000 and 20,000 units.


Studies have already shown that selenium deficiencies increase the virulence of RNA viruses (Sars-Cov2 is an RNA coronavirus). Other correlations have been established between selenium intake and mortality due to certain viruses such as HIV (AIDS) or hepatitis B.

With regard to Covid-19 and selenium, the data from China are particularly interesting. China has both the most selenium deficient population and the population with the highest selenium levels. A comparison of the infected cases that had to be treated for Covid-19 shows that regions deficient in selenium are significantly more affected than regions non deficient.

Selenium has an antiviral effect via several mechanisms of action. The good news is that nuts are rich in selenium, especially Brazil nuts, and are a great source of various vitamins and minerals, in addition to protein and fiber. The recommended selenium dose would be 50 to 100 micrograms per day (ug/day).


Dietary sources of zinc are fish and seafood (especially oysters), meat, liver, nuts and seeds. The mechanisms of action of the antiviral effect of zinc are not clear, but the inhibition of certain enzymes necessary for the replication of viruses could explain its benefits. Trials are underway to improve the effect of hydroxychloroquine by adding zinc to treated patients. The new synergy of the drug and this mineral could reduce the replication of the virus. Either way, there are several food sources as well as supplements that can help you increase your zinc intake. The recommended daily allowance would be 8 to 11 milligrams (mg/day). In the long term, do not exceed 50 mg/day orally.

Other vitamins and minerals

Some researchers have looked into the question of which supplements could be beneficial in the current situation to be better protected or, again, to be ready to face Covid-19. In searching the scientific literature, I identified two studies on the subject that considered a large number of publications and scientific studies in order to recommend the approaches they consider relevant.

A review of the scientific literature (Calder et al, 2020), carried out by 4 researchers from different countries, suggests considering the intake of certain supplements as being essential for the proper functioning of the immune system for optimal protection against viruses. Researchers retain vitamin A, B6, B12, C, D, E, folic acid (B9), zinc, iron, selenium, magnesium, copper and omega-3s. The authors recommend taking a multivitamin in addition to a balanced diet.

Another study, a systematic review this time (Jayawardena et al, 2020), considered 43 publications relating to controlled human studies, including immunological measures, for viral respiratory tract infections. Studies involving vitamins (13), minerals (8), nutraceuticals (18) and probiotics (4) were included. This study found that vitamin A and vitamin D, selenium and zinc, some probiotics, and some supplement formulations work to boost or stimulate the immune system. Without going into details, know that the authors concluded that the use of vitamins, minerals and certain formulations is appropriate, both in prevention and in the treatment of cases of Covid-19 infection. They underline the importance of the quality of the products considered (choose carefully the quality of the products you will use and ask the opinion of your pharmacist!).

Plants of Traditional Chinese Medicine.

In one of the articles in Vitoli’s blog (Natural Products: and what if we told you the truth?), my good friend, Dr. Éric Simard, mentions that a 2015 Nobel Prize winner in medicine, Youyou Tu, received the award for isolating an antiviral molecule from a plant used in Traditional Chinese Medicine. She received a Nobel Prize for the identification of a new plant-based antiviral agent used to treat malaria.

There are plants already known for their non-specific antiviral effects and it is of course interesting to wonder if some of these plants could be useful in combating Covid-19. I’ve attended training on modulating the immune system recently. The training presented the significant effects of three plants in particular for which the mechanisms of action were scientifically documented: astragalus (Astragalus membranaceus), echinacea (Echinacea purpurea) and elderberry (Sambucus nigra).

Looking through the literature, I found two studies that specifically looked at the use of Traditional Chinese Medicine to combat Covid-19. As we can imagine, the Chinese use their traditional medicines to try to prevent and treat Covid-19, in addition to contemporary medicine. Among the plants most used for this purpose, coming from monitoring in 23 provinces of China: Astragalus membranaceus, Glycyrrhizae uralensis, Saposhnikoviae divaricata, Rhizoma Atractylodis Macrocephalae, Lonicerae Japonicae Flos, Fructus Forsythiae, Atractylodis Rhizoma rugizosa rugizosa and Cyrtomium fortune J. Sm.

Interestingly, astragalus is both one of the most widely used plants and one of the most widely used components of Traditional Chinese Medicine. As mentioned, astragalus has mechanisms of action known for its antiviral effects. Also, among the plants I mentioned previously, it should be noted that echinacea (Echinacea purpurea), which you probably already know, is a plant native to North America and therefore not part of Traditional Chinese Medicine.

Chinese researchers hope to use hundreds of years of Traditional Chinese Medicine to find new antivirals for Covid-19, or a future virus. They stress, however, the importance that these clinical studies, which are currently being carried out in China, be carried out with standardized extracts (the composition of which is well established).


In conclusion, I would like to come back to the fact that certain groups and certain professionals hastened to say, at the beginning of the pandemic, that no supplement could be useful, because nothing had been demonstrated. Indeed, nothing was demonstrated, but does that mean that nothing can be useful? It is a new virus with many unknowns, so why reject the use of so-called “natural” products when there is no precedent for this pandemic, no instruction manual on how to proceed? Throwing them out is like the saying, throwing the baby out with the bathwater!

From this article, you can see that scientific knowledge allows us to identify supplements that can help both with prevention and treatment. The pandemic requires that we consider all the possibilities that can be explored to increase our chances of saving lives. Hospitals in Quebec have even now included the dosage of vitamin D in severely ill patients in order to supplement them in the event of a deficiency. Honestly, I think we should be quick to recommend that all our aging people take a vitamin D supplement and tell them to eat nuts for selenium and zinc.

Also note that in the area of supplements, the knowledge of different professionals is quite variable, even among health professionals. It is important to be well informed and to use quality products. In any case, I supplement myself adequately and I recommend everyone to take the same precautions … You can never be too careful!


André Perreault, Pharmacist



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