Published online May 27, 2020.
https://doi.org/10.3947/ic.2020.52.2.224
Dear Editor:
We appreciate the comment from Hemilä et al [1]. Previous studies based on in-vitro experiments have identified that high dosage intravenous Vit-C with copper and/or iron is virucidal [2]. However, despite these studies, the in-vivo virucidal activity of Vit-C has not been confirmed in detail. Previously, your meta-analyses of clinical trial data showed that regular Vit-C intake shortened the duration of the common cold by 8% [3]. However, coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus (severe acute respiratory syndrome coronavirus 2) whose genome sequence differs from other human coronaviruses causing the common cold [4]. Moreover, two recent clinical trials have demonstrated no significant difference in the development of sepsis, or severe acute respiratory failure, between Vit-C and non-Vit-C groups. In the CITRIS-ALI trial, no significant difference was found between the Vit-C (50 mg/kg every 6 hours for 96 hours) and placebo groups in the primary outcomes measured. These included modified Sequential Organ Failure Assessment score, C-reactive protein levels, and thrombomodulin levels at 168 hours. However, secondary outcome measures did differ between the groups with 28-day all-cause mortality significantly lower and intensive care unit-free days significantly shorter in the placebo groups than in the Vit-C groups [5]. The Vitamin C, hydrocortisone and thiamine in patients with septic shock (VITAMINS) trial also reported that among patients with septic shock, a combination of intravenous Vit-C, hydrocortisone, and thiamine did not significantly improve the primary outcome measure (duration of time alive and free of vasopressor administration over 7 days) compared with that after the intravenous hydrocortisone treatment alone [6].
Although Vit-C generally exhibits low toxicity, taking >2 g of Vit-C per day may cause adverse gastrointestinal events including abdominal pain, diarrhea, and/or nausea. Although Vit-C is a water-soluble vitamin, with excess excreted in the urine, it can contribute to the formation of renal stones [7]. Additionally, glucose-6-phosphate dehydrogenase (G6PD) deficiency, a genetic condition that results in inadequate G6PD levels, can cause hemolytic anemia following intravenous Vit-C treatment [8].
Currently, multiple clinical trials investigating the effect of Vit-C on severe COVID-19 are on going [9]. However, this therapy can only be considered, and therefore incorporated into treatment guidelines, based on sufficient confirmatory research results. For now, we will have to wait.
Conflict of Interest:No conflicts of interest.
Author Contributions:
Conceptualization: SBK, JSY.
Data curation: SBK, JSY.
Formal analysis: SBK, JSY.
Investigation: SBK.
Methodology: SBK.
Project administration: JSY.
Resources: SBK.
Software: SBK.
Supervision: JSY.
Validation: JSY.
Visualization: SBK.
Writing - original draft: SBK.
Writing - review & editing: JSY.
References
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Hemilä H, Chalker E. Vitamin C as a possible therapy for COVID-19. Infect Chemother 2020;52:222–223.
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Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2013;(1):CD000980
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Fowler AA 3rd, Truwit JD, Hite RD, Morris PE, DeWilde C, Priday A, Fisher B, Thacker LR 2nd, Natarajan R, Brophy DF, Sculthorpe R, Nanchal R, Syed A, Sturgill J, Martin GS, Sevransky J, Kashiouris M, Hamman S, Egan KF, Hastings A, Spencer W, Tench S, Mehkri O, Bindas J, Duggal A, Graf J, Zellner S, Yanny L, McPolin C, Hollrith T, Kramer D, Ojielo C, Damm T, Cassity E, Wieliczko A, Halquist M. Effect of vitamin C infusion on organ failure and biomarkers of inflammation and vascular injury in patients with sepsis and severe acute respiratory failure: The CITRIS-ALI randomized clinical trial. JAMA 2019;322:1261–1270.
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Fujii T, Luethi N, Young PJ, Frei DR, Eastwood GM, French CJ, Deane AM, Shehabi Y, Hajjar LA, Oliveira G, Udy AA, Orford N, Edney SJ, Hunt AL, Judd HL, Bitker L, Cioccari L, Naorungroj T, Yanase F, Bates S, McGain F, Hudson EP, Al-Bassam W, Dwivedi DB, Peppin C, McCracken P, Orosz J, Bailey M, Bellomo R. VITAMINS Trial Investigators. Effect of vitamin C, hydrocortisone, and thiamine vs hydrocortisone alone on time alive and free of vasopressor support among patients with septic shock: the vitamins randomized clinical trial. JAMA 2020;323:423–431.
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U.S. National Library of Medicine. ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world. [14 May 2020].Available at: https://clinicaltrials.gov/.
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