Low level of Vitamin C and dysregulation of Vitamin C transporter might be involved in the severity of COVID- 19 Infection

With an exponential increase in COVID-19 infection rate and mortality in an ongoing global pandemic, researchers, clinicians, and government agencies are focusing on repurposing drugs with known safety profiles. Previously known beneficial outcomes following high doses of vitamin C therapy in clinical studies have made this vitamin a frontline candidate for possible COVID-19 treatment. Also, there are very limited side effects and patients have high tolerability to ascorbic acid high doses. Currently, there are approximately 30 ongoing clinical trials registered using Vitamin C alone or in combination with other drugs looking at the efficacy behind treating COVID-19 infections on Clinicaltrial.gov and International Clinical Trials Registry Platform (World Health Organization). However, as of the date of writing, there are no published, peer-reviewed manuscripts or data sets looking at the effectiveness of either high dose IV or oral vitamin C in treating and limiting the symptoms of COVID-19 positive patients.

Based on the literature mentioned above, high dose intravenous vitamin C therapy has been shown to have a range of effectiveness from moderate to high in preventing and limiting the duration of viral infections, with the most beneficial effect coming in those with reduced ascorbic acids levels. The vitamin C treatment is known for its beneficial role in preventing/ neutralizing inflammatory response, reducing oxidative stress, and stimulating interferons and other antiviral cytokines. Vitamin C is drug of choice in this critical time because of its known high dose tolerability and little or no side effects. It is possible that Vitamin C might help in a certain population of COVID-19 infected patients. The previous moderate success of vitamin C supplementation in human clinical studies may be due to several factors depending on the subject’s age, race, levels of vitamin C transporter expression, and polymorphism in the vitamin C transporter, etc. Future clinical studies should be designed and conducted with all these factors taken into consideration, specifically vitamin C transporter expression and polymorphism. We recommend that the factors mentioned above should be considered at the start of clinical trials and during the analysis of the outcome of clinical findings. It will be interesting to see if vitamin C can help specifically in treating COVID-19 infected patients who are older, have underlying conditions or belong to African American populations. Furthermore, there is an urgent need to investigate the direct relationship between serum/plasma vitamin C levels in COVID-19 infection rate and severity.


Vitamin C as prophylaxis and adjunctive medical treatment for COVID-19?

COVID-19 pneumonia and its progression to respiratory failure appear to be driven by an immune hyperreaction in which IL-6 and ET-1 play an important role. Vitamin C can reduce these (and other) inflammatory mediators in various inflammatory condi- tions, and is clinically beneficial in (non-COVID-19) hypertensive and/or diabetic obese adult patients. Considering the weight of the evidence and because vitamin C is cheap and safe, an oral low dose (1!2 g/d) may be useful prophylactically, and in cases of severe COVID-19, a (very) high-dose regimen may be beneficial. Ongoing clinical trials are expected to provide more definitive evidence.


Can Zn Be a Critical Element in COVID-19 Treatment?

Zinc plays crucial roles in many aspects of life. In the course of infection, the immunomodulatory role of Zn is well evident. In the current pandemic of SARS-CoV-2, Zn supplement could play an important role to treat COVID-19 patients such as (i) added immune boosting effects with anti-viral drugs and (ii) stopping SARS-CoV-2 replication in infected cells, if combined with chloroquine. In view of this discussion, oral Zn supplement can be given using a suitable form of Zn-salt.


The Potential Impact of Zinc Supplementation on COVID-19 Pathogenesis

In this perspective, we reviewed the most important literature on the role of zinc homeostasis during viral infections, focusing on the potential benefits of zinc supplementation to prevent and treat SARS-CoV2 infections. Although data specifically on SARS-CoV2 are unfortunately still pending and randomized controlled studies have not been conducted, the enumerated evidence from the literature strongly suggests great benefits of zinc supplementation. Zinc supplementation improves the mucociliary clearance, strengthens the integrity of the epithelium, decreases viral replication, preserves antiviral immunity, attenuates the risk of hyper-inflammation, supports anti-oxidative effects and thus reduces lung damage and minimized secondary infections. Especially older subjects, patients with chronic diseases and most of the remaining COVID-19 risk groups would most likely benefit. Although studies are needed testing the effect of zinc as therapeutic option for established disease, preventive supplementation of subjects from risk groups should begin now, as zinc is a cost-efficient, globally available and simple to use option with little to no side effects. The first clinical trials on zinc supplementation alone and in combination with other drugs such as chloroquine have been registered. Thus, first results and treatment regimens regarding zinc supplementation for COVID-19 risk groups and patients can be anticipated soon.


Probiotics in viral infections, with a focus on COVID-19: A Systematic Review

We described the ecacy of probiotics for the prevention or treatment of viral-based infectious diseases; more than 20 strains improved the anti-inflammatory interleukins and anti-body production against viruses. Moreover, virus titres were lowered after probiotics supplementation periods. The large number of viral species and their subtypes as well as the high mutation rate of viruses do not allow scientists to discover appropriate vaccines and antiviral drugs, so, the administration of pro/prebiotics – as immune function modulators and antibiotic-related side effects removers – is recommended. Although further detailed research is necessary, the authors recommend researchers/physicians/dietitians to use probiotics as more rational adjunctive option in COVID-19 pandemic, especially in mechanically ventilated patients.


The potential application of probiotics and prebiotics for the prevention and treatment of COVID-19

Probiotics are live microorganisms that confer health benefits when consumed in adequate amounts, including enhanced immune activity and the clearance of respiratory tract infections. It is evident that probiotics can reduce the incidence and severity of diseases, suggesting their promise for treating or preventing COVID-19. Probiotics could help prevent COVID-19 by maintaining the human GI or lung microbiota because dysbiosis plays a major role in the susceptibility of people to infectious diseases. In vitro and clinical studies are required to examine the potential preventive and curative effects of probiotics against SARS-CoV-2 infection.