There is, at present, an ongoing scientific debate about selenium supplementation and the possible prevention of COVID-19 disease. What is the evidence that selenium supplementation of individuals with sub-optimal selenium status might help to prevent the infection?
The answer from a group of longstanding selenium researchers is that selenium supplementation does not have “a sufficient direct antiviral effect to prevent infection.” Instead, selenium supplementation acts “by decreasing the harmful effects of the virus on the host” [Rayman 2024].
Selenium supplementation “does not necessarily prevent infection but rather decreases the severity and mortality resulting from the infection” [Rayman 2024]. The important thing to focus on is the interaction between the human host selenium status and infectious virus strain and virulence [Beck 2003].
Effect of SARS-CoV-2 Infection On Host Selenoprotein Status
Prof. Margaret P. Rayman and her co-authors highlight the clinical correlations between selenium status and COVID-19 outcomes. For example, China has populations with the lowest and the highest selenium status in the world. In 2020, Zhang et al examined the data on the reported cure rate of COVID-19 in Chinese cities with more than 40 cases. For selenium status, the researchers used data on hair selenium status. They found a significant association between the reported cure rate and the regional selenium concentration: infected individuals in cities with data showing higher hair selenium status had higher reported COVID-19 cure rates [Zhang 2020].
In their 2024 comment, Rayman et al acknowledge that the above-mentioned association is open to criticisms of confounding. There could conceivably be other factors affecting the cure rates. However, they believe that the Zhang study results point to the need for further research into the effect of selenium status on COVID-10 cure rates and death rates [Rayman 2024].
Moreover, Rayman et al say that there seems to be evidence that a SARS-CoV-2 virus infection can disrupt the body’s biosynthesis of certain selenoproteins. A SARS-CoV-2 infection can reduce the endogenous levels of these selenoproteins in the human host.
In fact, COVID-19 may do more than adversely affect overall selenoprotein expression. COVID-19 may also target the biochemistry of specific selenoproteins. Accordingly, Rayman et al say that it is urgent to continue the scientific investigation of the roles of selenium in COVID-19 illness [Rayman 2024].
The Authors of the Selenium and COVID-19 Comment
In the June 2024 issue of the journal Molecules, Prof. Rayman and a group of researchers with a total of 200 or more published articles on selenium responded to an earlier review paper by Ambra et al. entitled “Could Selenium Supplementation Prevent COVID-19? A Comprehensive Review of Available Studies” [Ambra 2024; Rayman 2024].
In their review, Ambra et al had discussed several selenium and COVID-19 research papers. Rayman et al disagreed with most of Ambra’s assessments of the published work. They wrote a detailed rebuttal, highlighting inaccuracies and misinterpretations in the review article by Ambra et al [Rayman 2024]. The following well-known selenium researchers were among the authors writing and publishing the rebuttal.
Margaret P. Rayman, University of Surrey, Guildford, UK, is the corresponding author for the rebuttal article. She is the author of two frequently cited reviews on selenium and human health that were published in The Lancet [Rayman 2000; Rayman 2012].
Lutz Schomburg, Charité-Universitätsmedizin, Berlin, Germany, and his team have published several highly respected selenium studies. Schomburg is the author of the seminal journal article entitled “Selenoprotein P – Selenium transport protein, enzyme and biomarker of selenium status” [Schomburg 2022].
Melinda Beck, University of North Carolina, Chapel Hill, NC, USA, was the first researcher to show that selenium deficiency can result in viral mutations that make non-virulent viruses pathogenic and virulent [Beck 2003].
Conclusion: Selenium Status and COVID-19 Disease
The take-home message from Rayman et al [2024] is the following:
- Selenium status varies around the world, depending upon the content of selenium in the regional soil and the regional diet.
- Enzymes containing selenocysteine are a key factor in the ameliorating effect of selenium on COVID-19 outcomes.
- COVID-19 disease may adversely affect the biosynthesis of these seleno-enzymes.
- More research is needed in the relationship between selenium status and the severity and mortality of COVID-19 disease.
Sources
Ambra R, Melloni S, Venneria E. Could selenium supplementation prevent COVID-19? A comprehensive review of available studies. Molecules. 2023 May 16;28(10):4130.
Beck MA, Levander OA, Handy J. Selenium deficiency and viral infection. J Nutr. 2003 May;133(5 Suppl 1):1463S-7S.
Rayman MP, Schomburg L, Zhang J, Taylor EW, Du Laing G, Beck M, Hughes DJ, Heller R. Comment on Ambra et al. Could selenium supplementation prevent COVID-19? A comprehensive review of available studies. Molecules 2023, 28, 4130. Molecules. 2024 May 24;29(11):2466.
Rayman MP. Selenium and human health. Lancet. 2012 Mar 31;379(9822):1256-68.
Rayman MP. The importance of selenium to human health. Lancet. 2000 Jul 15;356(9225):233-41.
Schomburg L. Selenoprotein P – Selenium transport protein, enzyme and biomarker of selenium status. Free Radic Biol Med. 2022 Oct;191:150-163.
Zhang J, Taylor EW, Bennett K, Saad R, Rayman MP. Association between regional selenium status and reported outcome of COVID-19 cases in China. Am J Clin Nutr. 2020 Jun 1;111(6):1297-1299.
The information presented in this review article is not intended as medical advice. The information should not be used as such.