Zinc is important for the immune system

– also for Covid-19 disease

May 18 2020

In continuation of the previous two newsletters on Vitamin D and Selenium, a little important information about Zinc and its importance to the immune system is now presented here.

In these corona times, it is especially necessary that we each optimize our immune system so that we are well prepared for a possible new wave in about half a year from now, when people’s deposits of vitamin D again are declining.

In the Western part of the world, about 25% of the population has some level of zinc deficiency, especially the elderly, people with high alcohol consumption, people with chronic infections, those who get certain types of medicine, and elite athletes, who use up their magnesium and zinc.

Zinc is part of more than 200 different enzyme systems and is a prerequisite for normal growth and cell formation and a well-functioning immune system.

There is solid evidence that zinc deficiency leads to increased susceptibility to infection. Since zinc supplementation has also been found to reduce the duration of a cold, various zinc lozenges have been tried, and a Cochrane study of 18 studies found that 75 mg of zinc a day could reduce the duration of cold symptoms in healthy people, provided the zinc tablets were given within the first 24 hours after symptom onset.

The effect lies, among other things, in the skin and mucous membranes, where zinc is necessary for the cell replication that the body initiates when an infection is to be fought. This is especially true regarding the growth, maturation and differentiation of circulating lymphocytes, T cells and the killer cells, NK cells that we need to fight viruses.

In 2010, an in vitro study showed that zinc inhibits another coronavirus, namely SARS-CoV, which caused an epidemic in 2002. Zinc has a direct antiviral effect by inhibiting SARS-CoV RNA polymerase, which is a prerequisite for virus replication.

There is no specific study yet on the effect of zinc on the current CoV-Sars-2, but natural connections are looked for and, for example, the current Covid-19 disease is characterized by many people’s losing the sense of taste and smell, which is also seen in the case of zinc deficiency.
But it could be coincidence.

We have to take zinc all the time, as it is not stored specifically. It is not difficult to get enough zinc here in Denmark, just by eating real food and not industrial synthetic ‘plastic’ food. Zinc is found in meat, seafood, organ meat, fish, eggs, legumes, cereals, dairy products, green vegetables, fruits and berries. An intake of 20-30 mg per day is enough.

If you take zinc as a supplement, remember that it can reduce the copper content of the body, as zinc will upregulate the metallothionein synthesis, which can cause copper loss. This is probably not of great importance here in Denmark, where a large pig production has given us all a solid copper supplement.

In any case, we need zinc to optimize our immune system, so we are ready to fight an virus infection.

Now you have read about vitamin D, selenium and zinc in relation to the immune system.
The next newsletter to arm your immune system against Covid-19 will be about Vitamin C.

Take care of yourself and others,

Claus Hancke, MD,
Specialist in general medicine


  • Read Scott A, Obeid S et al. The role of Zinc in antiviral immunity.(2019) Adv Nutr 2019;10:696–710
  • Skalny et al: Zinc and respiratory tract infections: Perspectives for Covid-19. Int J Molecular Med. April 13, 2020
  • Mossad S, Macknin M, Mendendorp S, et al. Zinc Gluconate Lozenges for Treating the Common Cold: A Randomized, Double-Blind, Placebo-Controlled Study. Annals of Internal Medicine 15 July 1996
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