|LETTER TO THE EDITOR
|Year : 2021 | Volume
| Issue : 3 | Page : 216-217
Is high-dose zinc supplementation effective in reducing the symptoms of severe acute respiratory syndrome Coronavirus 2 infection?
Chidiebere Emmanuel Okechukwu
Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
|Date of Submission||16-Apr-2021|
|Date of Decision||30-Apr-2021|
|Date of Acceptance||06-May-2021|
|Date of Web Publication||05-Jul-2021|
Dr. Chidiebere Emmanuel Okechukwu
Department of Public Health and Infectious Diseases, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Okechukwu CE. Is high-dose zinc supplementation effective in reducing the symptoms of severe acute respiratory syndrome Coronavirus 2 infection?. Curr Med Issues 2021;19:216-7
|How to cite this URL:|
Okechukwu CE. Is high-dose zinc supplementation effective in reducing the symptoms of severe acute respiratory syndrome Coronavirus 2 infection?. Curr Med Issues [serial online] 2021 [cited 2021 Aug 1];19:216-7. Available from: https://www.cmijournal.org/text.asp?2021/19/3/216/320651
Several experimental and clinical investigations are ongoing regarding the possible antiviral mechanisms, and standard dose of zinc (Zn) supplementation for prevention and therapeutic use against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one such option. At present, there are no robust and substantial evidence to recommend either for or oppose the use of elemental Zn for the treatment of coronavirus disease 2019 (COVID-19). However, there are complications regarding decreased intestinal absorption of copper and suppression of the immune system with the use of high-dose Zn over a long period. Furthermore, Thomas et al. evaluated the efficacy of high-dose Zn gluconate in minimizing the duration of SARS-CoV-2 symptoms, and they found that it did not significantly decrease the duration of COVID-19 symptoms compared with standard of care. According to their report, 50 mg of Zn gluconate was administered to the patients at bedtime. However, 50 mg of Zn gluconate is different from 50 mg of elemental Zn. Zn gluconate 50 mg contains 14.3% of elemental Zn by weight, which is equivalent to 7 mg of Zn. Besides, the recommended dietary allowance (RDA) for Zn is 8 mg for women, and 11 mg for adult men., Therefore, it is not a “high-dose Zn” as stated by Thomas et al. in the title of their study. Thomas et al. did not report the Zn plasma levels of the participants before the trial, and also they did not report whether the participants were using iron supplements before and during the trial. High-dose Zn supplement interacts with iron supplement when taken together or when taken 1 hour before or 2 hours after ingesting an iron supplement and vice versa, and this may result to the inhibition of Zn absorption and bioavailability depending on their ratio (excess of iron inhibits Zn absorption and vice versa) and on the trace element status of an individual. Amino acids, such as L-histidine and methionine, have positive effects on Zn absorption and have been used for Zn supplementation. Furthermore, Zn ionophores can be used to increase labile Zn within cells, and quercetin can act as a Zn ionophore, transporting Zn cations through the plasma membrane, hence improving the biological functions of Zn.
In conclusion, further randomized controlled blinded clinical trials are required to substantiate the efficacy of high-dose elemental Zn supplementation on the duration of symptoms associated with SARS-CoV-2 infection compared with the standard of care and a placebo control group. Moreover, before the commencement of further clinical trials, clinical investigators should stratify COVID-19 patients according to age, sex, race, body mass index, severity and duration of symptoms, and underlying illness (e.g. gastrointestinal disease, type 2 diabetes mellitus, cardiovascular diseases, and cancer) and analyze and compute the effects of Zn supplementation according to various risk groups. The nutritional status of COVID-19 patients should be well documented in further clinical trials. Clinicians should endeavor to improve the quality and standard of their research regarding nutrition and COVID-19.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Pal A, Squitti R, Picozza M, Pawar A, Rongioletti M, Dutta AK, et al.
Zinc and COVID-19: Basis of Current Clinical Trials [published online ahead of print, 2020 Oct 22]. Biol Trace Elem Res. 2020;1-11. doi:10.1007/s12011-020-02437-9.
Thomas S, Patel D, Bittel B, Wolski K, Wang Q, Kumar A, et al.
Effect of high-dose zinc and ascorbic acid supplementation vs. usual care on symptom length and reduction among ambulatory patients with SARS-CoV-2 Infection: The COVID A to Z randomized clinical trial. JAMA Netw Open 2021;4:e210369.
Lewis MR, Kokan L. Zinc gluconate: Acute ingestion. J Toxicol Clin Toxicol 1998;36:99-101.
Saper RB, Rash R. Zinc: An essential micronutrient. Am Fam Physician 2009;79:768-72.
Lönnerdal B. Dietary factors influencing zinc absorption. J Nutr 2000;130:1378S-83S.
Dabbagh-Bazarbachi H, Clergeaud G, Quesada IM, Ortiz M, O'Sullivan CK, Fernández-Larrea JB. Zinc ionophore activity of quercetin and epigallocatechin-gallate: From Hepa 1-6 cells to a liposome model. J Agric Food Chem 2014;62:8085-93.