Extra Dose of Vitamin C Based on a Daily Supplementation Shortens the Common Cold: A Meta-Analysis of 9 Randomized Controlled Trials

Vitamin C reduces the severity of common colds: a meta-analysis

BACKGROUND

Randomized trials have shown that vitamin C shortens the duration of common colds. Some trials reported greater effects on severe cold symptoms compared with mild symptoms. This review systematically compares the effects of vitamin C on severe and mild common cold symptoms.

METHODS

We included all placebo-controlled trials of orally administered vitamin C in doses of at least 1 g/day for the common cold for people in good health at baseline. The analysis was restricted to trials which reported both the total duration of the common cold, and the severity of the common cold measured using severity scales, the duration of more severe stages of the cold, or proxies for severe colds such as days indoors. Findings were pooled using the inverse variance, fixed effect options of the metacont function of the R package meta to calculate the ratio of means estimate.

RESULTS

Fifteen comparisons from 10 trials which reported both mild and severe symptoms were identified. All trials were randomized and double-blind. Compared to placebo, vitamin C significantly decreased the severity of the common cold by 15% (95% CI 9-21%). The direct comparison of the effect of vitamin C on mild and severe symptoms was limited to five comparisons which found that vitamin C had a significant benefit on the duration of severe symptoms. In this subset, there was a significant difference in the size of the effect of vitamin C on the overall duration of colds versus the duration of severe colds (P = 0.002), and vitamin C had no significant effect on the duration of mild symptoms.

CONCLUSIONS

The common cold is the leading cause of acute morbidity and a major cause of absenteeism from work and school. However, absenteeism is dependent on the severity of symptoms. The finding that vitamin C may have a greater effect on more severe measures of the common cold is therefore important. Further research on the therapeutic effects of vitamin C on the common cold should measure outcomes of differing levels of severity.

Low Levels of Serum and Intracellular Vitamin C in Hospitalized COVID-19 Patients

Vitamin C is a crucial micronutrient for human immune cell function and has potent antioxidant properties. It is hypothesized that vitamin C serum levels decline during infection. However, the precise mechanisms remain unknown. To gain deeper insights into the true role of vitamin C during infections, we aimed to evaluate the body's vitamin C storage during a SARS-CoV-2 infection. In this single-center study, we examined serum and intracellular vitamin C levels in peripheral blood mononuclear cells (PBMCs) of 70 hospitalized COVID-19 patients on the first and fifth days of hospitalization. Also, clinical COVID-19 severity was evaluated at these timepoints. Our findings revealed a high prevalence of hypovitaminosis C and vitamin C deficiency in hospitalized COVID-19 patients (36% and 15%). Moreover, patients with severe or critical disease exhibited a higher prevalence of low serum vitamin C levels than those with moderate illness. Serum vitamin C levels had a weak negative correlation with clinical COVID-19 severity classification on the day of hospitalization; however, there was no correlation with intracellular vitamin C. Intracellular vitamin C levels were decreased in this cohort as compared to a healthy cohort and showed further decline during hospitalization, while serum levels showed no relevant change. Based on this observation, it can be suggested that the reduction of intracellular vitamin C may be attributed to its antioxidative function, the need for replenishing serum levels, or enhanced turnover by immune cells. These data give an incentive to further investigate the role of intracellular vitamin C in a larger and more heterogeneous cohort as well as the underlying mechanisms.

Broad-Spectrum Antivirals Derived from Natural Products

Scientific advances have led to the development and production of numerous vaccines and antiviral drugs, but viruses, including re-emerging and emerging viruses, such as SARS-CoV-2, remain a major threat to human health. Many antiviral agents are rarely used in clinical treatment, however, because of their inefficacy and resistance. The toxicity of natural products may be lower, and some natural products have multiple targets, which means less resistance. Therefore, natural products may be an effective means to solve virus infection in the future. New techniques and ideas are currently being developed for the design and screening of antiviral drugs thanks to recent revelations about virus replication mechanisms and the advancement of molecular docking technology. This review will summarize recently discovered antiviral drugs, mechanisms of action, and screening and design strategies for novel antiviral agents.

Associations between sampling characteristics, nutritional supplemental taking and the SARS-CoV-2 infection onset in a cohort of Italian nurses

Background: The aim of the present study was to analyze any relations existed between sampling characteristics and the onset of the SARS-CoV-2 infection, also by considering the number of times that it occurred in a cohort of Italian nurses interviewed. Additionally, by considering the nutritional supplemental taking, this research wanted to assess any differences both in the onset and in the number of times which the infection occurred among participants. Method: An observational cohort study was carried out thorough all Italian nurses by advertising the questionnaire through some professional internet pages. Results: Work typology (p=0.021), ward Covid-19 (p=0.002) and regular meal assumption (p=0.019) significantly associated to the onset of the SARS-CoV-2 infection. Most of nurses who contracted the SARS-CoV-2 infection worked during the night shift (53.7%), 44.3% worked in a no-Covid-19 ward and 53% declared to have a regular meals’ assumption. Ward typology significantly associated to the times of the SARS-CoV-2 onset (p=0.003), as most of nurses who contracted almost one time the SARS-CoV-2 infection were employed in a no-Covid-19 ward (55.5%) and 54.1% of them declared to have a regular meals’ assumption. The onset of the Sars-CoV-2 infection seemed to be more present in the most part of the sample collect. Conclusion: The present study could be considered as pilot in this sense and also more studies will be performed in order to better relate the function of supplemental food intakes with a better functioning of the immune system.

The Use of Dietary Supplements and Their Association with COVID-19-Related Anxiety among Non-Institutionalized Elderly in Northern Greece

The elderly constitute a vulnerable group for increased anxiety and poor diet during the COVID-19 pandemic. There is limited research on the levels of COVID-19-related anxiety and dietary habits including dietary supplementation practices among the elderly and very elderly in Greece. A cross-sectional survey was conducted in 364 non-institutionalized elderly (65-74 y) and very elderly (≥75 y) living in northern Greece, with the aim to investigate the use of dietary supplements and their association with other factors, particularly the COVID-19-related anxiety. Levels of anxiety were assessed with the use of the Coronavirus Anxiety Scale (CAS-5). The percentage of dietary supplement users was 62.6%. The most popular dietary supplements used were vitamin D followed by vitamin C and multivitamin and mineral supplements. Multivariate analysis showed that the very elderly and overweight individuals were less likely to consume vitamin D supplements. Approximately a third of the participants (33.8%) exhibited signs of COVID-19-related anxiety but only 8% showed dysfunctional levels of anxiety. Regression analysis indicated that women, former smokers, and people exhibiting any sign of COVID-19 anxiety were approximately two times more likely to consume dietary supplements of any kind (Gender: OR 2.34, 95% CI 1.30-4.19; Smoking: OR 2.15, 95% CI: 1.08-4.26; COVID-19 anxiety: OR 2.16, 95 % CI: 1.20-3.91). Our results provide useful insights into the current practices of dietary supplement use in this population group and could be used by dietetic and medical associations as well as public authorities in the formulation of targeted, safe, and effective interventions for the protection of public health.

Retracted: Extra Dose of Vitamin C Based on a Daily Supplementation Shortens the Common Cold: A Meta-Analysis of 9 Randomized Controlled Trials

[This retracts the article DOI: 10.1155/2018/1837634.].

Vitamin C improves gut Bifidobacteria in humans

Aims: Numerous beneficial effects of vitamin C (ascorbic acid) supplementation have been reported in the literature. However, data on its effects toward the gut microbiome are limited. We assessed the effect of vitamin C supplementation on the abundance of beneficial bacterial species in the gut microbiome. Materials and methods: Stool samples were analyzed for relative abundance of gut microbiome bacteria using next-generation sequencing-based profiling and metagenomic shotgun analysis. Results: Supplementation with vitamin C increased the abundance of bacteria of the genus Bifidobacterium (p = 0.0001) and affected various species. Conclusion: The beneficial effects of vitamin C supplementation may be attributed to modulation of the gut microbiome and the consequent health benefits thereof.

Moodithaya S, K. A, Kumar Chatterjee P. Micronutrients- The crucial dietary elements in Covid-19 pandemic: A review

The mutation of the SARS-CoV-2 virus, which cause person-to-person transmission, is the pivotal reason for the pandemic outbreak in the year 2020. Infection symptoms include fever, dry cough, lethargy, severe pneumonia, respiratory distress syndrome, and death. COVID-19 induces a systemic inflammatory reaction that impairs the immune system, commonly known as cytokine release syndrome. Pro-inflammatory cytokines and chemokines are abundant in COVID-19 sufferers' bodies. COVID-19 has a disproportionate impact on the elderly, both directly and through several comorbidities associated with age. Nutrition is without hesitation, a crucial factor in maintaining good health. Some nutrients are essential for the immune system's health and function, exhibiting synergistic actions in critical immune response steps. Vitamin D, C, and Zinc stand out among these nutrients because they have immunomodulatory properties and help to maintain physical tissue barriers. Considering the viability of the virus, nutrients that boost the immunity henceforth the severity of viral infections declines with improved prognosis become important. As a result, the purpose of this review is to provide a complete outline of vitamins D, C, and zinc's involvement during the immune response towards infection, and to enlighten their commensal action of maintaining physical barriers including integument and mucous membrane. Appropriate vitamin D, C, and zinc consumption may represent a feasible pharmacological intervention during the COVID-19 pandemic due to the high surge in population interaction and the commencement of inflammation.  

Antioxidant Effects of Dietary Supplements on Adult COVID-19 Patients: Why Do We Not Also Use Them in Children?

Respiratory tract infections (RTIs) are very common in children, especially in the first five years of life, and several viruses, such as the influenza virus, Respiratory Syncytial Virus, and Rhinovirus, are triggers for symptoms that usually affect the upper airways. It has been known that during respiratory viral infections, a condition of oxidative stress (OS) occurs, and many studies have suggested the potential use of antioxidants as complementary components in prophylaxis and/or therapy of respiratory viral infections. Preliminary data have demonstrated that antioxidants may also interfere with the new coronavirus 2’s entry and replication in human cells, and that they have a role in the downregulation of several pathogenetic mechanisms involved in disease severity. Starting from preclinical data, the aim of this narrative review is to evaluate the current evidence about the main antioxidants that are potentially useful for preventing and treating Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in adults and to speculate on their possible use in children by exploring the most relevant issues affecting their use in clinical practice, as well as the associated evidence gaps and research limitations.

The diabetogenic effects of chronic supplementation of vitamin C or E in rats: Interplay between liver and adipose tissues transcriptional machinery of lipid metabolism

AIM

The chronic administration of vitamin C and E can differentially disrupt hepatic insulin molecular pathway in rats. Hence, this study evaluated their effects on lipogenesis in the liver and adipose tissue and investigated the possible involvement of microRNA (miR)-22/29a/27a in the induced impaired glucose tolerance.

MAIN METHODS

Wistar rats were orally supplemented with vitamin C (100, 200, and 500 mg/kg) or vitamin E (50, 100, and 200 mg/kg) for eight months.

KEY FINDINGS

Vitamin C or E at the highest doses significantly altered liver weight and index, serum and hepatic lipids, adiponectin, and liver enzymes; besides their reported unfavorable effect on glucose homeostasis. Vitamin C and E negatively affected peroxisome proliferator-activated receptor coactivator-1 (PGC-1α), sterol regulatory element-binding protein (SREBP)-1c/-2, miR-22/29a/27a expression, and adipose perilipin 1 to different extents, effects that were supported by the histopathological examination.

SIGNIFICANCE

The current study provides a deeper insight into the findings of our previous study and highlights the detrimental effects of chronic vitamins supplementation on lipid metabolism. Overall, these findings emphasize the damage caused by the mindless use of supplements and reinforce the role of strict medical monitoring, particularly during the new COVID-19 era during which numerous commercial supplements are claiming to improve immunity.

The Role of Diet and Supplements in the Prevention and Progression of COVID-19: Current Knowledge and Open Issues

A healthy diet and dietary supplements have gained attention as potential co-adjuvants in managing and preventing coronavirus disease 2019 (COVID-19). This paper critically reviews the current evidence regarding the impact of diet and supplements on the prevention and progression of COVID-19. According to available data, a healthy diet and normal weight are considered protective factors. Regarding dietary supplementation, the most robust results from human studies are for vitamin C, which appears to decrease inflammatory markers and suppress cytokine storm. A small, randomized trial showed that a high dose of vitamin D significantly reduced the need for intensive care unit treatment of patients requiring hospitalization for COVID-19. According to retrospective human studies, there is limited evidence for vitamin E and selenium supplements. Animal studies have investigated the effects of green tea and curcumin. Xanthohumol and probiotics, interesting for their antiviral, anti-inflammatory, and immunoregulatory properties, need formal clinical study. In summary, there is promising evidence supporting the role of diet and supplements as co-adjuvants in the treatment of COVID-19. Further studies and properly designed clinical trials are necessary to draw more robust conclusions; however, it is not unreasonable to take a pragmatic approach and promote the use of appropriate diet and supplements to counter the effects of COVID-19, ideally with a mechanism to assess outcomes.

Immunity-enhancing Micronutrients and Community Pharmacists: An Opportunity to Expand Self-Care Practices among the Public

Background: The urban lifestyle and environment pose a constant immune challenge to city dwellers. A major such challenge is influenza, which creates substantial public health and socio-economic burdens. The global healthcare paradigm has begun emphasizing the importance and cost-effectiveness of self-care in partnership with healthcare professionals such as community pharmacists for the management of mild ailments. For the general public, micronutrient supplementation is an affordable and potentially feasible self-care strategy for immunity enhancement and disease management. At the same time, micronutrient deficiencies are a serious public health concern in both developing and developed areas. Objective: This review focuses on the clinical evidence for the efficacy and safety of three key micronutrients — vitamins C, D and zinc — on respiratory infections. Key findings: These micronutrients are important for optimal immune function through their complementary roles in supporting both innate and adaptive immunity, as well as epithelial barriers. The need to improve public awareness of self-care in prevention and health management is highlighted by recent public health issues and the global fight against antimicrobial resistance. Community pharmacists could play a crucial role in empowering patient autonomy. Conclusion: With this review we aim to offer insights into the supplementation of these micronutrients as a self-care approach to the management of immune health.

Modifiable Host Factors for the Prevention and Treatment of COVID-19: Diet and Lifestyle/Diet and Lifestyle Factors in the Prevention of COVID-19

Many studies have shown that the immune system requires adequate nutrition to work at an optimal level. Not only do optimized nutritional strategies support the immune system, but they also reduce chronic inflammation. Nutritional supplements that are recommended for patients with critical illnesses are thought to also be effective for the coronavirus disease 2019 (COVID-19) patients in the intensive care unit. Some studies have recommended fresh fruits and vegetables, soy, nuts, and antioxidants, such as omega-3 fatty acids, to improve immune system activity. Although nutritional status is considered to be an important prognostic factor for patients with COVID-19, there is to date no sufficient evidence that optimal nutritional therapies can be beneficial for these patients. Some have argued that the COVID-19 pandemic is a good opportunity to test the effectiveness of nutritional intervention for infectious diseases. Many researchers have suggested that testing the proposed nutritional approaches for infectious diseases in the context of a pandemic would be highly informative. The authors of other review papers concluded that it is important to have a diet based on fresh foods, such as fruits, vegetables, whole grains, low-fat dairy products, and healthy fats (i.e., olive oil and fish oil), and to limit the intake of sugary drinks as well as high-calorie and high-salt foods. In this review, we discuss the clinical significance of functional food ingredients as complementary therapies potentially beneficial for the prevention or treatment of COVID-19. We believe that our review will be helpful to plan and deploy future studies to conclude these potentials against COVID-19, but also to new infectious diseases that may arise in the future.

Vitamin C stimulates RNA expression of human gingival fibroblasts proliferation and adhesion in cigarette smokers: An in vitro study

Background

Smoking and the severity of periodontal disease have long been associated. In Saudi Arabia, tobacco smoking is rising, contributing to the increased demand for products that counter its detrimental effects. The antioxidant properties of vitamin C (vit C) make it a powerful countermeasure to tobacco toxicity. Observation of these effects on human gingival fibroblasts (hGFs) would suggest use of vitamin C in future dental applications.

Aim

To examine the proliferation, adhesion, and expression of extracellular RNA in human gingival fibroblasts extracted from cigarette smokers when compared to never-smokers, in association with vitamin C.

Materials and Methods

Human gingival fibroblasts were extracted from Periodontal free sites of healthy adult male participants. Group 1; consisted of Heavy cigarette smokers (n = 1) while group 2 was never-smokers (n = 1). Collected cells were cultured and subcultured in supplemented growth medium. Vitamin C was then induced in the medium at the experimental sixth passage. RNA expression analysis using quantitative reverse transcriptase-polymerase chain reaction was performed to analyze the adhesion, proliferation, and extracellular matrix expression.

Results

Expression of the adhesion gene (CD44) in the smoker group was significantly downregulated than never-smoker group (p-value = 0.024). After the induction of vitamin C, the smoker samples showed a significant improvement in their gene expression levels. The extracellular genes involved in this study (COL1A1, LAMA3, and TGFB3) were significantly affected by the smoking status. In addition, the proliferation of MK167 and CCNB1 genes in smokers and never-smokers was increased.

Conclusion

Cigarette smoking affects the overall properties of human gingival fibroblasts’ adhesion, proliferation, and extra-cellular matrix formation. Furthermore, the addition of vitamin C affects these cellular properties in a positive manner.

Intravenous vitamin C use and risk of severity and mortality in COVID-19: A systematic review and meta-analysis

The administration of intravenous vitamin C (IV-VC) in treating patients with coronavirus disease 2019 (COVID-19) is still highly controversial. There have been no previous studies on the effect of IV-VC on the severity and mortality of COVID-19. Hence, we conducted a systematic review and meta-analysis to compare the disease severity and mortality in patients with COVID-19 who promptly received IV-VC treatment vs those who did not. We performed a comprehensive systematic search of seven health science databases, including PubMed, Embase, Cochrane Library, MEDLINE, Web of Science, China National Knowledge Infrastructure, and Wanfang Data, up to June 23, 2021. We identified a total of seven related articles, which were included in this study. This meta-analysis showed that IV-VC treatment did not affect disease severity compared with placebo treatment or usual care (odds ratio [OR], 0.70; 95% CI, 0.45 to 1.07; P = 0.10). In addition, no statistically significant difference in mortality was observed between patients who received IV-VC treatment and those who did not (OR, 0.64; 95% CI, 0.41 to 1.00; P = 0.05). Moreover, the adjusted meta-analysis revealed that the use of IV-VC did not influence disease severity (OR, 0.67; 95% CI, 0.34 to 1.31; P = 0.242) or mortality (OR, 1.02; 95% CI, 0.75 to 1.40; P = 0.877) in comparison with a control group. The results of this meta-analysis demonstrated that short-term IV-VC treatment did not reduce the risk of severity and mortality in patients with COVID-19.

Bias against Vitamin C in Mainstream Medicine: Examples from Trials of Vitamin C for Infections

Evidence has shown unambiguously that, in certain contexts, vitamin C is effective against the common cold. However, in mainstream medicine, the views on vitamin C and infections have been determined by eminence-based medicine rather than evidence-based medicine. The rejection of the demonstrated benefits of vitamin C is largely explained by three papers published in 1975-two published in JAMA and one in the American Journal of Medicine-all of which have been standard citations in textbooks of medicine and nutrition and in nutritional recommendations. Two of the papers were authored by Thomas Chalmers, an influential expert in clinical trials, and the third was authored by Paul Meier, a famous medical statistician. In this paper, we summarize several flaws in the three papers. In addition, we describe problems with two recent randomized trial reports published in JAMA which were presented in a way that misled readers. We also discuss shortcomings in three recent JAMA editorials on vitamin C. While most of our examples are from JAMA, it is not the only journal with apparent bias against vitamin C, but it illustrates the general views in mainstream medicine. We also consider potential explanations for the widespread bias against vitamin C.

Nutrient modulation of viral infection-implications for COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has put focus on the importance of a healthy immune system for recovery from infection and effective response to vaccination. Several nutrients have been under attention because their nutritional statuses showed associations with the incidence or severity of COVID-19 or because they affect several aspects of immune function. Nutritional status, immune function, and viral infection are closely interrelated. Undernutrition impairs immune function, which can lead to increased susceptibility to viral infection, while viral infection itself can result in changes in nutritional status. Here, we review the roles of vitamins A, C, D, and E, and zinc, iron, and selenium in immune function and viral infection and their relevance to COVID-19.

The Role of Micronutrients to Support Immunity for COVID-19 Prevention

The World Health Organization declared the novel coronavirus, named as SARS-CoV-2, as a global pandemic in early 2020 after the disease spread to more than 180 countries leading to tens of thousands of cases and many deaths within a couple of months. Consequently, this paper aims to summarize the evidence for the relationships between nutrition and the boosting of the immune system in the fight against the disease caused by SARS-CoV-2. This review, in particular, assesses the impact of vitamin and mineral supplements on the body's defence mechanisms against SARS-CoV-2. The results revealed that there is a strong relationship between the ingestion of biological ingredients like vitamins C-E, and minerals such as zinc, and a reduction in the effects of coronavirus infection. These can be received from either nutrition rich food sources or from vitamin supplements. Furthermore, these macromolecules might have roles to play in boosting the immune response, in the healing process and the recovery time. Hence, we recommend that eating healthy foods rich in vitamins C-E with zinc and flavonoids could boost the immune system and consequently protect the body from serious infections.

GRAPHICAL ABSTRACT

Supplemental Vitamins and Minerals for Cardiovascular Disease Prevention and Treatment: JACC Focus Seminar

This is an update of the previous 2018 systematic review and meta-analysis of vitamin and mineral supplementation on cardiovascular disease outcomes and all-cause mortality. New randomized controlled trials and meta-analyses were identified by searching the Cochrane library, Medline, and Embase, and data were analyzed using random effects models and classified by the Grading of Recommendations Assessment Development and Evaluation approach. This updated review shows similar findings to the previous report for preventive benefits from both folic acid and B vitamins for stroke and has been graded with moderate quality. No effect was seen for the commonly used multivitamins, vitamin D, calcium, and vitamin C, and an increased risk was seen with niacin (with statin) for all-cause mortality. Conclusive evidence for the benefit of supplements across different dietary backgrounds, when the nutrient is sufficient, has not been demonstrated.

Determining the impact of vitamin C use with the common cold on loss of labour and medical treatment costs for Turkey

Objectives

As one of the most common health problems, the common cold may lead to negative consequences such as work or school absenteeism, poor productivity and labour loss. Vitamin C supports immune system defences by supporting the various cellular functions of the immune system, both congenital and adaptive. The purpose of this study is to evaluate the use of vitamin C in white-collar workers and its impact on medical care costs and its impact on the workforce in association with the common cold.

Methods

For calculation of the effect of 1000 mg vitamin C daily on the workforce and possible healthcare services costs, a Markov-based model was simulated with 6 cycles consistent with the literature that constituted the model input for the 6-month common cold season. The simulated Markov model included parameters for the number of seasonal flu episodes with or without vitamin C use, the duration of the episodes, productivity loss and daily labour costs. The TreeAge Healthcare Pro 2020 program was used for the Markov model.

Key findings

The calculations revealed that the common cold lasted 0.47 days less with vitamin C use. The calculations revealed that the number of days absent from work is 0.38 days more without vitamin C use compared with vitamin C use. The calculations revealed that the medical treatment costs for the common cold is TL 1723.98. According to the analysis conducted based on the Markov model, the total cost of lost productivity and medical treatment that would occur in case of a common cold is TL 3704.97 with vitamin C use and TL 4223.26 without vitamin C use.

Conclusion

Based on the results of the analysis, we can suggest that regular vitamin C supplementation may prevent the impact of the common cold on public health and the resulting economic burden.

A Multidisciplinary Approach to Coronavirus Disease (COVID-19)

Since December 2019, humanity has faced an important global threat. Many studies have been published on the origin, structure, and mechanism of action of the SARS-CoV-2 virus and the treatment of its disease. The priority of scientists all over the world has been to direct their time to research this subject. In this review, we highlight chemical studies and therapeutic approaches to overcome COVID-19 with seven different sections. These sections are the structure and mechanism of action of SARS-CoV-2, immunotherapy and vaccine, computer-aided drug design, repurposing therapeutics for COVID-19, synthesis of new molecular structures against COVID-19, food safety/security and functional food components, and potential natural products against COVID-19. In this work, we aimed to screen all the newly synthesized compounds, repurposing chemicals covering antiviral, anti-inflammatory, antibacterial, antiparasitic, anticancer, antipsychotic, and antihistamine compounds against COVID-19. We also highlight computer-aided approaches to develop an anti-COVID-19 molecule. We explain that some phytochemicals and dietary supplements have been identified as antiviral bioproducts, which have almost been successfully tested against COVID-19. In addition, we present immunotherapy types, targets, immunotherapy and inflammation/mutations of the virus, immune response, and vaccine issues.

Nutritional management of diabetes mellitus during the pandemic of COVID-19: a comprehensive narrative review

Objectives

According to the recent epidemiological studies, patients with diabetes mellitus (DM) may be at higher risk of hospitalization due to COVID-19. Regarding the important role of nutrition on the immunity, the present review article aimed to outline nutritional support of DM during the outbreak of COVID-19 with a mechanistic insight.

Methods

Searches were performed in PubMed/MEDLINE, ScienceDirect, Scopus, and Google Scholar databases from 2000 until December 2020 using the following keywords. All relevant clinical and experimental studies published in English were included.

Results

Evidences revealed that hyperglycemia is a significant predictor of some viral infections including COVID-19 which can exacerbate the complications of DM. According to the literature review, adequate intake of dietary protein, fiber, essential fatty acids and some micronutrients especially vitamins D, C, B12, folate, zinc and selenium has beneficial effects on the prevention and treatment of COVID-19 in diabetic patients through modulation of innate and adaptive immune responses or direct effects on virus enzymes or the rate of cell entrance.

Conclusions

It is well understood that malnutrition may increase susceptibility to viral infections and disease progression. Therefore, considering nutritional status of diabetic patients and reasonable supplementation of the above mentioned nutrients can ameliorate the symptoms of COVID-19 in DM. However, further well-designed clinical trials are needed to determine their therapeutic dose.

Medicinal Plants and Isolated Molecules Demonstrating Immunomodulation Activity as Potential Alternative Therapies for Viral Diseases Including COVID-19

Plants have been extensively studied since ancient times and numerous important chemical constituents with tremendous therapeutic potential are identified. Attacks of microorganisms including viruses and bacteria can be counteracted with an efficient immune system and therefore, stimulation of body's defense mechanism against infections has been proven to be an effective approach. Polysaccharides, terpenoids, flavonoids, alkaloids, glycosides, and lactones are the important phytochemicals, reported to be primarily responsible for immunomodulation activity of the plants. These phytochemicals may act as lead molecules for the development of safe and effective immunomodulators as potential remedies for the prevention and cure of viral diseases. Natural products are known to primarily modulate the immune system in nonspecific ways. A number of plant-based principles have been identified and isolated with potential immunomodulation activity which justify their use in traditional folklore medicine and can form the basis of further specified research. The aim of the current review is to describe and highlight the immunomodulation potential of certain plants along with their bioactive chemical constituents. Relevant literatures of recent years were searched from commonly employed scientific databases on the basis of their ethnopharmacological use. Most of the plants displaying considerable immunomodulation activity are summarized along with their possible mechanisms. These discussions shall hopefully elicit the attention of researchers and encourage further studies on these plant-based immunomodulation products as potential therapy for the management of infectious diseases, including viral ones such as COVID-19.

Nutrition and Immunity in COVID-19

Nutrition can strongly influence infection trajectories by either boosting or suppressing the immune system. During the recently emerged pandemic of coronavirus disease 2019 (COVID-19), individuals who possess diets high in fat, refined carbohydrates, and sugars have shown to be highly prone to the disease and associated adverse outcomes. Both micronutrients and macronutrients provide benefits at different stages of the infection. Thus, using appropriate nutritional recommendations and interventions is necessary to combat the infection in patients with COVID-19 in both outpatient and inpatient settings.

Micronutrients and bioactive substances: Their potential roles in combating COVID-19

OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic is seriously threatening public health and setting off huge economic crises across the world. In the absence of specific drugs for COVID-19, there is an urgent need to look for alternative approaches. Therefore, the aim of this paper was to review the roles of micronutrients and bioactive substances as potential alternative approaches in combating COVID-19.

METHODS

This review was based on the literature identified using electronic searches in different databases.

RESULTS

Vitamins (A, B, C, D, and E), minerals (selenium and zinc), and bioactive substances from curcumin, echinacea, propolis, garlic, soybean, green tea, and other polyphenols were identified as having potential roles in interfering with spike glycoproteins, angiotensin converting enzyme 2, and transmembrane protease serine 2 at the entry site, and inhibiting activities of papain-like protease, 3 chymotrypsin-like protease, and RNA-dependent RNA polymerase in the replication cycle of severe acute respiratory syndrome coronavirus 2. Having immunomodulating, antiinflammatory, antioxidant, and antiviral properties, such micronutrients and bioactive substances are consequently promising alterative nutritional approaches to combat COVID-19.

CONCLUSIONS

The roles of micronutrients and bioactive substances in the fight against COVID-19 are exciting areas of research. This review may suggest directions for further study.

G6PD deficiency, redox homeostasis, and viral infections: implications for SARS-CoV-2 (COVID-19)

The COVID-19 pandemic has so far affected more than 45 million people and has caused over 1 million deaths worldwide. Infection with SARS-CoV-2, the pathogenic agent, which is associated with an imbalanced redox status, causes hyperinflammation and a cytokine storm, leading to cell death. Glucose-6-phosphate dehydrogenase (G6PD) deficient individuals may experience a hemolytic crisis after being exposed to oxidants or infection. Individuals with G6PD deficiency are more susceptible to coronavirus infection than individuals with normally functioning G6PD. An altered immune response to viral infections is found in individuals with G6PD deficiency. Evidence indicates that G6PD deficiency is a predisposing factor of COVID-19.

Nutritional perspectives for the prevention and mitigation of COVID-19

Worldwide, there is an array of clinical trials under way to evaluate treatment options against coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2. Concurrently, several nutritional therapies and alternative supportive treatments are also being used and tested to reduce the mortality associated with acute respiratory distress in patients with COVID-19. In the context of COVID-19, improved nutrition that includes micronutrient supplementation to augment the immune system has been recognized as a viable approach to both prevent and alleviate the severity of the infection. The potential role of micronutrients as immune-boosting agents is particularly relevant for low- and middle-income countries, which already have an existing high burden of undernutrition and micronutrient deficiencies. A systematic literature review was performed to identify nutritional interventions that might prevent or aid in the recovery from COVID-19. The PubMed, ScienceDirect, Cochrane, Scopus, Web of Science, and Google Scholar databases were searched electronically from February to April 2020. All abstracts and full-text articles were examined for their relevance to this review. The information gathered was collated under various categories. Deficiencies of micronutrients, especially vitamins A, B complex, C, and D, zinc, iron, and selenium, are common among vulnerable populations in general and among COVID-19 patients in particular and could plausibly increase the risk of mortality. Judicious use of need-based micronutrient supplementation, alongside existing micronutrient fortification programs, is warranted in the current global pandemic, especially in low- and middle-income economies.

Nutritional perspectives for the prevention and mitigation of COVID-19

Worldwide, there is an array of clinical trials under way to evaluate treatment options against coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2. Concurrently, several nutritional therapies and alternative supportive treatments are also being used and tested to reduce the mortality associated with acute respiratory distress in patients with COVID-19. In the context of COVID-19, improved nutrition that includes micronutrient supplementation to augment the immune system has been recognized as a viable approach to both prevent and alleviate the severity of the infection. The potential role of micronutrients as immune-boosting agents is particularly relevant for low- and middle-income countries, which already have an existing high burden of undernutrition and micronutrient deficiencies. A systematic literature review was performed to identify nutritional interventions that might prevent or aid in the recovery from COVID-19. The PubMed, ScienceDirect, Cochrane, Scopus, Web of Science, and Google Scholar databases were searched electronically from February to April 2020. All abstracts and full-text articles were examined for their relevance to this review. The information gathered was collated under various categories. Deficiencies of micronutrients, especially vitamins A, B complex, C, and D, zinc, iron, and selenium, are common among vulnerable populations in general and among COVID-19 patients in particular and could plausibly increase the risk of mortality. Judicious use of need-based micronutrient supplementation, alongside existing micronutrient fortification programs, is warranted in the current global pandemic, especially in low- and middle-income economies.

The coronavirus disease (COVID-19) - A supportive approach with selected micronutrients

Worldwide the pandemic of COVID-19 spreads rapidly and has had an enormous public health impact with substantial morbidity and mortality especially in high-risk groups, such as older people and patients with comorbidities like diabetes, dementia or cancer. In the absence of a vaccine against COVID-19 there is an urgent need to find supportive therapies that can stabilize the immune system and can help to deal with the infection, especially for vulnerable groups such as the elderly. This is especially relevant for our geriatric institutions and nursing homes. A major potential contributing factor for elderly is due to their high incidence of malnutrition: up to 80% among the hospitalized elderly. Malnutrition results when adequate macronutrients and micronutrients are lacking in the diet. Often missing in public health discussions around preventing and treating COVID-19 patients are nutritional strategies to support optimal function of their immune system. This is surprising, given the importance that nutrients play a significant role for immune function. Several micronutrients, such as vitamin D, retinol, vitamin C, selenium and zinc are of special importance supporting both the adaptive and innate immune systems. As suboptimal status or deficiencies in these immune-relevant micronutrients impair immune function and reduces the resistance to infections, micronutrient deficiencies should therefore be corrected as soon as possible, especially in the elderly and other vulnerable groups. According to epidemiological, experimental and observational studies, some case reports and a few intervention studies the supplementation of vitamin D and/or zinc are promising. The multiple anti-inflammatory and immunomodulatory effects of Vitamin D could explain its protective role against immune hyper reaction and cytokine storm in patients with severe COVID-19. A randomized, placebo-controlled intervention study even shows that high dose vitamin D supplementation promotes viral clearance in asymptomatic and mildly symptomatic SARS-CoV-2 positive individuals. Besides, the data of a recent prospective study with COVID-19 patients reveal that a significant number of them were zinc deficient. The zinc deficient patients had more complications and the deficiency was associated with a prolonged hospital stay and increased mortality. Thus, immune-relevant micronutrients may help to increase the physiological resilience against COVID-19.

Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis

Acute respiratory tract infections (ARIs) are a leading cause of ill-health and death globally. Individual or multiple micronutrients have been shown to modulate immune function and affect the risk and severity of a number of infectious diseases. We systematically reviewed the evidence on the impact of micronutrient supplements to reduce the occurrence of ARIs and shorten the duration of ARI symptoms among adults. Random effects meta-analyses were conducted to estimate the pooled effects of vitamin D, vitamin C, zinc and multiple micronutrient supplementation (MMS) on the occurrence of ARIs and the duration of ARI symptoms. Vitamin D supplementation reduced the risk of ARI (risk ratio (RR)=0.97; 95% CI 0.94 to 1.00; p=0.028) and shortened the duration of symptoms (per cent difference: -6% (95% CI -9% to -2%; p=0.003)). The RR of vitamin D to prevent ARI was farther from the null when diagnosis was based on clinical diagnosis or laboratory testing, compared with self-report and when the loading dose was <60 000 IU. Vitamin C supplementation reduced the risk of ARIs (RR=0.96; 95% CI 0.93 to 0.99; p=0.01) and shortened the duration of symptoms (per cent difference: -9% (95% CI -16% to -2%; p=0.014)). The effect of vitamin C on preventing ARI was stronger among men and in middle-income countries, compared with women and high-income countries, respectively. Zinc supplementation did not reduce the risk of ARIs but shortened the duration of symptoms substantially (per cent difference: -47% (95% CI -73% to -21%; p=0.0004)). Our synthesis of global evidence from randomised controlled trials indicates that micronutrient supplements including zinc, vitamins C and D, and multiple micronutrient supplements may be modestly effective in preventing ARIs and improving their clinical course. Further research is warranted to better understand the effectiveness that individual or multiple micronutrients have on SARS-CoV-2 infection and treatment outcomes.

Efficacy and safety of vitamin C in the management of acute respiratory infection and disease: A rapid review

BRIEF OVERVIEW

Current evidence from published systematic reviews indicate that oral intake of vitamin C may assist with symptoms of acute viral respiratory infections (ARI) by reducing fever and chills, relieving chest pain and assist in reducing symptoms of common cold-induced asthma. Intravenous (IV) vitamin C administration may reduce the need for vasopressor support and the duration of mechanical ventilations in critically ill patients in hospital. COVID-19 has similar signs and symptoms of ARI. Further studies involving patients with COVID-19, either through administration of oral vitamin C in mild cases or IV vitamin C in critical cases, would be advantageous to examine if it is safe and efficacious.

VERDICT

Oral vitamin C may assist with the symptoms of acute respiratory viral infections (ARI) and common cold-induced asthma but no studies have been identified justifying oral vitamin C for the prevention or treatment of coronavirus infections including COVID-19. When taken at onset of ARI, oral vitamin C may reduce the duration of symptoms including fever, chest pain, chills and bodily aches and pains. It may also reduce the incidence of hospital admission and duration of hospital stays. For individuals admitted to hospital with community-acquired pneumonia, vitamin C may improve respiratory function in more severe cases. No major adverse events nor interactions were reported by either method of administration. However, there is an absence of high quality, contemporary clinical research examining this topic. Current evidence suggests further studies are needed to better understand the value of both oral and IV vitamin C for ARI, including COVID-19.

Possible application of high-dose vitamin C in the prevention and therapy of coronavirus infection

Coronaviruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses increase oxidative stress in the body leading to cellular and tissue damage. To combat this, administration of high-dose vitamin C (ascorbic acid or ascorbate), in addition to standard conventional supportive treatments, has been shown to be a safe and effective therapy for severe cases of respiratory viral infection. Morbidity, mortality, infectiveness and spread of infectious diseases are dependent on the host-pathogen relationship. Given the lack of effective and safe antiviral drugs for coronaviruses, there should be more attention in supporting host immune defence, cytoprotection and immunoregulation. Implementation of high-dose vitamin C therapy could dramatically reduce the need for high doses of corticosteroids, antibacterials and antiviral drugs that may be immunosuppressive, adrenal depressive and toxic, complicating the disease course. In order to effectively fight the novel SARS-CoV-2 virus, medical professionals should explore readily available pharmaceutical and nutritional therapeutic agents with proven antioxidant, anti-inflammatory and immunosupportive properties. Supplemental vitamin C may also provide additional benefits for the prevention of viral infections, shorten the disease course and lessen complications of the disease.

The Role of Vitamin C as Adjuvant Therapy in COVID-19

Background and objective

The anti-inflammatory properties of vitamin C (VC) and the promising results it has shown in the treatment for common cold have prompted clinicians to use it as adjuvant therapy in the treatment of COVID-19. The purpose of this study was to find out the role of VC as adjunctive therapy in coronavirus disease 2019 (COVID-19).

Methodology

This study was conducted from March to July 2020 in the COVID-19 unit of a tertiary care hospital in Karachi. In this randomized controlled trial (RCT), one group received the intervention [50 mg/kg/day of intravenous (IV) VC] along with the standard therapy, and the other group received standard therapy only. Data such as age, gender, vitals, and biochemical values as well as outcomes including the number of days required for treatment, hospital stay, need for ventilation, and mortality were compared between the two groups and recorded using a self-structured questionnaire.

Results

COVID-19 patients who received IV VC became symptom-free earlier (7.1 ± 1.8 vs. 9.6 ± 2.1 days, p-value: <0.0001) and spent fewer days in the hospital (8.1 ± 1.8 vs. 10.7 ± 2.2 days, p-value: <0.0001) compared to those who received standard therapy only. However, there was no significant difference in the need for mechanical ventilation (p-value: 0.406) and mortality (p-value: 0.31) between the two groups.

Conclusion

VC can significantly improve clinical symptoms in patients affected with COVID-19; however, it had no impact on mortality and the need for mechanical ventilation. More large-scale studies are required to further assess the role of VC in the treatment of COVID-19.

Mini-Review on the Roles of Vitamin C, Vitamin D, and Selenium in the Immune System against COVID-19

Low levels of micronutrients have been associated with adverse clinical outcomes during viral infections. Therefore, to maximize the nutritional defense against infections, a daily allowance of vitamins and trace elements for malnourished patients at risk of or diagnosed with coronavirus disease 2019 (COVID-19) may be beneficial. Recent studies on COVID-19 patients have shown that vitamin D and selenium deficiencies are evident in patients with acute respiratory tract infections. Vitamin D improves the physical barrier against viruses and stimulates the production of antimicrobial peptides. It may prevent cytokine storms by decreasing the production of inflammatory cytokines. Selenium enhances the function of cytotoxic effector cells. Furthermore, selenium is important for maintaining T cell maturation and functions, as well as for T cell-dependent antibody production. Vitamin C is considered an antiviral agent as it increases immunity. Administration of vitamin C increased the survival rate of COVID-19 patients by attenuating excessive activation of the immune response. Vitamin C increases antiviral cytokines and free radical formation, decreasing viral yield. It also attenuates excessive inflammatory responses and hyperactivation of immune cells. In this mini-review, the roles of vitamin C, vitamin D, and selenium in the immune system are discussed in relation to COVID-19.

Food policy, nutrition and nutraceuticals in the prevention and management of COVID-19: Advice for healthcare professionals

BACKGROUND

The 2019 novel coronavirus (2019-nCoV) represents an ongoing major global health crisis with a potentially unprecedented death toll and socio-economic impact in the modern era. Measures taken to reduce the rate of transmission are too unprecedented, but are deemed necessary. The extensive strain on public health services has meant that individual agency is increasingly called for. To support this, there is a need to review policy and procedure governing the food and commerce industries in particular. Additionally, it is necessary to convey a more comprehensive and nuanced understanding of relevant diet and lifestyle factors to both healthcare practitioners and the general public.

SCOPE AND APPROACH

To our knowledge, a review of possible additional measures for healthcare proffesionals, which includes the possible nutritional management COVID-19 pandemic does not yet exist.Key Findings and Conclusions: This review identifies i) changing trends in consumer awareness and purchasing patterns in response to COVID-19, and their potential future implications for the food and food-commerce industry ii) problematic elements of policy relevant to the outbreak of COVID-19, including the handling of wild-life and food-commerce, ii) newly emergent technologies in food science which represent viable and cost-effective means to reduce the risk of transmission of coronavirus, such as anti-microbial packaging, iii) important nutritional considerations with regard to coronavirus disease prevention and management, including nutrition in early infancy, and the role of select micronutrients (vitamins and minerals), phytochemicals and probiotics in conferring protection against both viral infection and pathogenicity.

Overview of the possible role of vitamin C in management of COVID-19

The mainstay of management of coronavirus disease 2019 (COVID-19) is mainly supportive as to date there is no effective antiviral treatment, apart from remdesivir which has been approved by Food and Drug administration (FDA) for treatment of COVID-19, or vaccine. Supplementation with micronutrients, such as vitamins and minerals, has gained an increasing interest as part of the supportive management of COVID-19. Vitamin C levels in serum and leukocytes are depleted during the acute stage of infection owing to increased metabolic demands. High-dose vitamin C supplement helps to normalise both serum and leukocytes vitamin C levels. Vitamin C has multiple pharmacological characteristics, antiviral, anti-oxidant, anti-inflammatory and immunomodulatory effects, which make it a potential therapeutic option in management of COVID-19. The use of high dose of intravenous vitamin C for management of COVID-19 in China and the United Stated has shown promising results. There were no reported adverse reactions with the short-term use of high dose of vitamin C. Given the fact that vitamin C is cheap, available and safe drug with beneficial effects in management of viral infections and critically ill patients reported in previous clinical trials, it is sensible to add it to COVID-19 management protocol particularly if the current ongoing clinical trials testing the effect of vitamin C in management of COVID-19 show positive results.

The Long History of Vitamin C: From Prevention of the Common Cold to Potential Aid in the Treatment of COVID-19

From Pauling's theories to the present, considerable understanding has been acquired of both the physiological role of vitamin C and of the impact of vitamin C supplementation on the health. Although it is well known that a balanced diet which satisfies the daily intake of vitamin C positively affects the immune system and reduces susceptibility to infections, available data do not support the theory that oral vitamin C supplements boost immunity. No current clinical recommendations support the possibility of significantly decreasing the risk of respiratory infections by using high-dose supplements of vitamin C in a well-nourished general population. Only in restricted subgroups (e.g., athletes or the military) and in subjects with a low plasma vitamin C concentration a supplementation may be justified. Furthermore, in categories at high risk of infection (i.e., the obese, diabetics, the elderly, etc.), a vitamin C supplementation can modulate inflammation, with potential positive effects on immune response to infections. The impact of an extra oral intake of vitamin C on the duration of a cold and the prevention or treatment of pneumonia is still questioned, while, based on critical illness studies, vitamin C infusion has recently been hypothesized as a treatment for COVID-19 hospitalized patients. In this review, we focused on the effects of vitamin C on immune function, summarizing the most relevant studies from the prevention and treatment of common respiratory diseases to the use of vitamin C in critical illness conditions, with the aim of clarifying its potential application during an acute SARS-CoV2 infection.

The Role of Micronutrients in Support of the Immune Response against Viral Infections

Viral infections are a leading cause of morbidity and mortality worldwide, and the importance of public health practices including handwashing and vaccinations in reducing their spread is well established. Furthermore, it is well known that proper nutrition can help support optimal immune function, reducing the impact of infections. Several vitamins and trace elements play an important role in supporting the cells of the immune system, thus increasing the resistance to infections. Other nutrients, such as omega-3 fatty acids, help sustain optimal function of the immune system. The main aim of this manuscript is to discuss of the potential role of micronutrients supplementation in supporting immunity, particularly against respiratory virus infections. Literature analysis showed that in vitro and observational studies, and clinical trials, highlight the important role of vitamins A, C, and D, omega-3 fatty acids, and zinc in modulating the immune response. Supplementation with vitamins, omega 3 fatty acids and zinc appears to be a safe and low-cost way to support optimal function of the immune system, with the potential to reduce the risk and consequences of infection, including viral respiratory infections. Supplementation should be in addition to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19).

COVID-19 Outbreak: Pathogenesis, Current Therapies, and Potentials for Future Management

At the end of 2019, a novel coronavirus (CoV) was found at the seafood market of Hubei province in Wuhan, China, and this virus was officially named coronavirus diseases 2019 (COVID-19) by World Health Organization (WHO). COVID-19 is mainly characterized by severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) and creates public health concerns as well as significant threats to the economy around the world. Unfortunately, the pathogenesis of COVID-19 is unclear and there is no effective treatment of this newly life-threatening and devastating virus. Therefore, it is crucial to search for alternative methods that alleviate or inhibit the spread of COVID-19. In this review, we try to find out the etiology, epidemiology, symptoms as well as transmissions of this novel virus. We also summarize therapeutic interventions and suggest antiviral treatments, immune-enhancing candidates, general supplements, and CoV specific treatments that control replication and reproduction of SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV).

Reply to "Overstated Claims of Efficacy and Safety. Comment On: Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections. Nutrients 2020, 12, 1181"

We thank Vorland et al [...].

Overstated Claims of Efficacy and Safety. Comment On: "Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect Against Viral Infections". Nutrients 2020, 12, 1181

Calder et al [...].

[Nutritional support for critically ill patients suffering from SARS-CoV-2 infection]

Patients with severe cases of COVID-19 are at high nutritional risk during their ICU stay. Prolonged immobilization associated with an exacerbated systemic inflammatory response is a major provider of ICU-acquired muscle weakness. Early enteral nutrition is recommended to gradually reach the energy target of 25 kcal/kg/day and protein target of 1.3 g/kg/day around D4. The occurrence of a Refeeding syndrome should be closely monitored. In case of feeding intolerance refractory to a prokinetic treatment, complementary or total parenteral nutrition is advised, favouring new generation mixed lipid emulsions (containing fish oil) and regular monitoring of triglyceridemia. Nutrition care of critically ill patients should be carried out with limited procedures that may pose a risk of contamination for the healthcare staff.

Importance of Dietary Changes During the Coronavirus Pandemic: How to Upgrade Your Immune Response

The new coronavirus pandemic continues to spread causing further public health, social, and economic issues. The disparities in the rates of death between countries poses questions about the importance of lifestyle habits and the immune status of populations. An exploration of dietary habits and COVID-19-related death might unravel associations between these two variables. Indeed, while both nutritional excess and deficiency are associated with immunodeficiency, adequate nutrition leading to an optimally functioning immune system may be associated with better outcomes with regards to preventing infection and complications of COVID-19, as well as developing a better immune response to other pathogenic viruses and microorganisms. This article outlines the key functions of the immune system and how macronutrients, micronutrients, and metabolites from the gut microbiome can be essential in the development of an efficient immune system. In addition, the effects of intermittent fasting on the inflammatory state as well as metabolic parameters will be discussed.

The efficacy of a compounded micronutrient supplement on the incidence, duration, and severity of the common cold: A pilot randomized, double-blinded, placebo-controlled trial

Purpose

Viral upper respiratory infections are associated with significant health and economic impact. This study sought to determine the efficacy of routine immune system micronutrient supplementation on the incidence, duration and severity of common cold symptoms.

Methods

This pilot study was a randomized, double-blinded, placebo-controlled trial of N = 259 with asymptomatic participants aged 18 to 65 in two cold seasons of 2016 and 2017. The treatment group received an immune system targeted micronutrient caplet, while the placebo group received a micronized cellulose caplet externally identical to the treatment caplet. Weekly surveys were sent electronically to participants to document common cold incidence, duration and severity. Primary statistical results were obtained using mixed-effects logistic regressions to account for longitudinal measurements for participants.

Results

The odds of acquiring an upper respiratory infection, adjusted for potential confounders, was estimated to be 0.74 times lower in the treatment group (p = 0.14). The odds of reporting specific symptoms were statistically lower in the treatment arm compared to the placebo arm for runny nose (OR = 0.53, p = 0.01) and cough (OR = 0.51, p = 0.04). Shorter durations of runny nose and cough were also observed in the treatment arm compared to placebo (both p < 0.05). There was no significant difference in severity of symptoms in either group. The observed proportion of reported cold symptoms in the treatment group was lower compared to the placebo group between late January and February in two consecutive cold seasons. Given the physical, workplace and economic impact of upper respiratory infections, this low cost and low risk intervention should be further studied with more robust investigation and meticulous experimental design.

Key Aspects in Nutritional Management of COVID-19 Patients

This review deals with the relationship among nutrition, the immune system, and coronavirus disease 2019 (COVID-19). The influence of nutrients and bioactive molecules present in foodstuffs on immune system activity, the influence of COVID-19 on the nutritional status of the patients, and the dietary recommendations for hospitalized patients are addressed. Deficient nutritional status is probably due to anorexia, nausea, vomiting, diarrhea, hypoalbuminemia, hypermetabolism, and excessive nitrogen loss. There is limited knowledge regarding the nutritional support during hospital stay of COVID-19 patients. However, nutritional therapy appears as first-line treatment and should be implemented into standard practice. Optimal intake of all nutrients, mainly those playing crucial roles in immune system, should be assured through a diverse and well-balanced diet. Nevertheless, in order to reduce the risk and consequences of infections, the intakes for some micronutrients may exceed the recommended dietary allowances since infections and other stressors can reduce micronutrient status. In the case of critically ill patients, recently published guidelines are available for their nutritional management. Further, several natural bioactive compounds interact with the angiotensin-converting enzyme 2 (ACE2) receptor, the gateway for severe acute respiratory syndrome (SARS) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Natural bioactive compounds can also reduce the inflammatory response induced by SARS-CoV-2. These compounds are potential beneficial tools in the nutritional management of COVID-19 patients.

Food or medication? The therapeutic effects of food on the duration and incidence of upper respiratory tract infections: a Review of the literature

PURPOSE

Upper respiratory tract infections are common in children and adults. Antiviral treatments are only available for specific groups of patients, stimulating the distribution of over-the-counter medication to relieve the symptoms for the other patients. Studies about whole foods and their effect on the incidence and duration of upper respiratory tract infections were reviewed.

METHODS

Randomized controlled trials and case-control studies available on MEDLINE, Web of Science, Cochrane Library and Embase were included.

RESULTS AND CONCLUSIONS

Thirty-three studies were included. The incidence of respiratory infections or symptoms was shown to be reduced in some studies when probiotics, prebiotics, growing-up milk, fish oil, kiwi, garlic and xylitol were taken. Duration was favorably influenced by the intake of elderberry, kiwi, probiotics and fish oil. When the risk of bias and repetition is taken into account, probiotics and elderberry repeatedly show favorable effects. Prudent conclusions can be made in selective patient groups. However, the studies were diverse and were only performed by a few study groups.

Tackle the free radicals damage in COVID-19

COVID-19 is a severe pandemic which has caused a devastating amount of loss in lives around the world, and yet we still don't know how to appropriately treat this disease. We know very little about the pathogenesis of SARS-CoV-2, the virus which induces the COVID-19. However, COVID-19 does share many similar symptoms with SARS and influenza. Previous scientific discoveries learned from lab animal models and clinical practices shed light on possible pathogenic mechanisms in COVID-19. In the past decades, accumulated scientific findings confirmed the pathogenic role of free radicals damage in respiratory virus infection. Astonishingly very few medical professionals mention the crucial role of free radical damage in COVID-19. This hypothesis aims to summarize the crucial pathogenic role of free radical damage in respiratory virus induced pneumonia and suggest an antioxidative therapeutic strategy for COVID-19.

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Additional scheme figure is attached.