Patients with Community Acquired Pneumonia Exhibit Depleted Vitamin C Status and Elevated Oxidative Stress

Vitamin D promotes autophagy to inhibit LPS-induced lung injury via targeting cathepsin D

Pneumonia is a frequent-occurring event in children death. Vitamin D (VD) can alleviate inflammatory response and it might be a promising adjunct to antibiotics for the treatment of acute childhood pneumonia. This study intended to uncover the relevant mechanism of VD in pneumonia. For simulating inflammatory condition, BEAS-2B cells were induced using lipopolysaccharide (LPS). Cell viability was detected using cell counting kit-8 (CCK-8) method, and cell apoptosis was detected using flow cytometry and western blot. Inflammatory cytokines as well as oxidative stress markers were detected using enzyme-linked immunosorbent assay (ELISA) and corresponding assays. Western blot evaluated the contents of cathepsin D (CTSD), apoptosis- and autophagy-related proteins. Through real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) and western blot, the transfection efficiency of overexpression (OV)-CTSD was detected. Immunofluorescence assay detected light chain 3 (LC3II) level. Through SuperPred database analysis, VD can target CTSD. VD was revealed to suppress viability damage, inflammatory response, oxidative stress, and autophagy injury in BEAS-2B cells induced by LPS via targeting CTSD. However, the protective effects exhibited by VD against LPS-induced viability damage, inflammatory response, and oxidative stress in BEAS-2B cells were all counteracted by autophagy inhibitor 3-methyladenine (3-MA). Collectively, VD alleviated the severity of LPS-induced lung injury by promoting autophagy through targeting CTSD.

Prevalence, risk factors, and clinical outcomes of vitamin C deficiency in adult hospitalized patients in high-income countries: a scoping review

BACKGROUND

Assessment for vitamin C deficiency (VCD) is rarely undertaken in an acute hospital setting in high-income countries. However, with growing interest in VCD in community settings, there is emerging evidence investigating the prevalence and impact of VCD during hospitalization.

OBJECTIVES

In this scoping review, the prevalence of VCD in adult hospitalized patients is explored, patient characteristics are described, and risk factors and clinical outcomes associated with VCD are identified.

METHODS

A systematic scoping review was conducted in accordance with the PRISMA-ScR framework. The Ovid MEDLINE, Ovid Embase, Scopus, CINAHL Plus, Allied and Complementary Medicine Database, and the Cochrane Library databases were searched for interventional, comparative, and case-series studies that met eligibility criteria, including adult hospital inpatients in high-income countries, as defined by the Organization for Economic Co-operation and Development, that reported VCD prevalence using World Health Organization reference standards. These standards define VCD deficiency as plasma or serum vitamin C level <11.4 µmol/L, wholeblood level <17 µmol/L, or leukocytes <57 nmol/108 cells.

RESULTS

Twenty-three articles were included, representing 22 studies. The cumulative prevalence of VCD was 27.7% (n = 2494; 95% confidence interval [CI], 21.3-34.0). High prevalence of VCD was observed in patients with severe acute illness and poor nutritional status. Scurvy was present in 48% to 62% of patients with VCD assessed in 2 studies (n = 71). Being retired (P = 0.015) and using excessive amounts of alcohol and tobacco (P = 0.0003) were independent risk factors for VCD (n = 184). Age was not conclusively associated with VCD (n = 631). Two studies examined nutrition associations (n = 309); results were inconsistent. Clinical outcomes for VCD included increased risk of frailty (adjusted odds ratio, 4.3; 95%CI, 1.33-13.86; P = 0.015) and cognitive impairment (adjusted odds ratio, 2.93; 95%CI, 1.05-8.19, P = 0.031) (n = 160).

CONCLUSIONS

VCD is a nutritional challenge facing the healthcare systems of high-income countries. Research focused on early identification and treatment of patients with VCD is warranted.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework ( https://doi.org/10.17605/OSF.IO/AJGHX ).

Serum SOD1 level predicts the severity and prognosis of community-acquired pneumonia patients

BACKGROUND

Superoxide dismutase 1 (SOD1) is one of the most important participants of antioxidant enzyme system in biological system. Previous studies have found that SOD1 is associated with many inflammatory diseases. The goal of this study was to assess the associations of serum SOD1 with the severity and prognosis in community-acquired pneumonia (CAP) patients by a prospective cohort study.

METHODS

CAP patients were enrolled from the Second Affiliated Hospital of Anhui Medical University. Peripheral blood samples were gathered. The level of serum SOD1 was detected through enzyme linked immunosorbent assay (ELISA). Clinical characteristics and demographic information were analyzed.

RESULTS

The level of serum SOD1 was gradually upregulated with elevated CAP severity scores. Spearman correlation coefficient or Pearson rank correlation analyses indicated that serum SOD1 was strongly connected with many clinical parameters among CAP patients. Further linear and logistic regression analyses found that the level of serum SOD1 was positively associated with CRB-65, CURB-65, SMART-COP, and CURXO scores among CAP patients. Moreover, serum higher SOD1 at admission substantially increased the risks of ICU admission, mechanical ventilation, vasoactive agent usage, death, and longer hospital stays during hospitalization. Serum SOD1 level combination with CAP severity scores elevated the predictive abilities for severity and death compared with alone serum SOD1 and CAP severity scores in CAP patients during hospitalization.

CONCLUSION

The level of serum SOD1 is positively associated with the severity and poor prognosis in CAP patients, suggesting that SOD1 is implicated in the initiation and progression of CAP. Serum SOD1 may be regarded as a biomarker to appraise the severity and prognosis for CAP patients.

Association between rheumatoid arthritis and serum vitamin C levels in Adults: Based on the National health and Nutrition Examination survey database

This study attempted to investigate relationship between rheumatoid arthritis and serum vitamin C levels using data from National Health and Nutrition Examination Survey (NHANES). The NHANES database aims to collect health, nutrition, biological, and behavioral data from a nationally representative sample of the population. This study utilizes NHANES data from three cycles: 2003-2004, 2005-2006, and 2017-2018, extracting data on the prevalence of rheumatoid arthritis and serum vitamin C levels. A generalized linear model is used to evaluate the association between the two. A total of 12,665 participants were included in the final analysis. Serum vitamin C levels were significantly higher in the non-rheumatoid arthritis group compared to the rheumatoid arthritis group (0.63 vs. 0.59, P = 0.042). Generalized linear model analysis showed that higher serum vitamin C levels were associated with a decreased risk of rheumatoid arthritis (OR = 0.62, 95 %CI: 0.40-0.98, P = 0.034). Stratified analysis revealed a significant interaction between non-hypertensive individuals and rheumatoid arthritis with serum vitamin C levels (P < 0.05). After adjusting for confounding factors, serum vitamin C levels remained significantly associated with rheumatoid arthritis in all models (P < 0.05). Restricted cubic spline results indicated that serum vitamin C levels above 0.95 mg/dL could help prevent rheumatoid arthritis. Increasing dietary vitamin C intake through supplementation was found to raise serum vitamin C levels. There was a significant association between rheumatoid arthritis and serum vitamin C levels, indicating that high levels of serum vitamin C may be a protective factor against rheumatoid arthritis.

Use of immunomodulatory therapy as part of comprehensive treatment of non-severe community-acquired pneumonia and its long-term results

Background

This study investigates the efficiency of two different types of immunomodulators for the treatment of non-severe community-acquired pneumonia (CAP) and assesses their long-term effects.

Methods

The study included 55 patients with non-severe CAP. Group 1 (control) received only standard CAP therapy; the other two groups received immunomodulators simultaneously with the standard therapy: bacterial lysate for group 2 and azoximer bromide (AzB) for group 3. TNF and IL-6 concentrations were determined on the day of hospitalization as well as on days 13 and 60 of follow-up. For 2 years, we monitored the incidence of low respiratory tract infections (LRTIs) in the same patients with CAP (n=55).

Results

The overall duration of all symptoms was lower in the immunomodulator groups compared with the control group. During treatment, TNF and IL-6 concentrations decreased on days 13 and 60 in all patients; in patients who received immunomodulators, TNF and IL-6 were reliably lower than in control patients. IL-6 concentration decreased on day 60 in the bacterial lysate and AzB treatment groups and did not differ (p=0.72). The odds ratio for the development of LRTIs in the AzB group was 0.15 (0.02-0.93) (p=0.04), suggesting its protective effect.

Conclusion

Inclusion of immunomodulators in the basic treatment of non-severe CAP reduces the duration of symptoms and is associated with improvement of the pro-inflammatory cytokine profile. In 2 years of follow-up, the long-term effects of the immunomodulatory therapy showed a statistically significant lower incidence of LRTIs in the AzB group only. However, given the small sample size of this study, further clinical studies are needed.

Adjunctive intravenous then oral vitamin C for moderate and severe community-acquired pneumonia in hospitalized adults: feasibility of randomized controlled trial

Patients hospitalised with community acquired pneumonia (CAP) have low peripheral blood vitamin C concentrations and limited antioxidant capacity. The feasibility of a trial of vitamin C supplementation to improve patient outcomes was assessed. Participants with moderate and severe CAP (CURB-65 ≥ 2) on intravenous antimicrobial treatment were randomised to either intravenous vitamin C (2.5 g 8 hourly) or placebo before switching to oral intervention (1 g tds) for 7 days when they were prescribed oral antimicrobial therapy. Of 344 patients screened 75 (22%) were randomised and analysed. The median age was 76 years, and 43 (57%) were male. In each group, one serious adverse event that was potentially intervention related occurred, and one subject discontinued treatment. Vitamin C concentrations were 226 µmol/L in the vitamin C group and 19 µmol/L in the placebo group (p < 0.001) after 3 intravneous doses. There were no signficant differences between the vitamin C and placebo groups for death within 28 days (0 vs. 2; p = 0.49), median length of stay (69 vs. 121 h; p = 0.07), time to clinical stability (22 vs. 49 h; p = 0.08), or readmission within 30 days (1 vs. 4; p = 0.22). The vitamin C doses given were safe, well tolerated and saturating. A randomised controlled trial to assess the efficacy of vitamin C in patients with CAP would require 932 participants (CURB-65 ≥ 2) to observe a difference in mortality and 200 participants to observe a difference with a composite endpoint such as mortality plus discharge after 7 days in hospital. These studies are feasible in a multicentre setting.

The Role of Diet and Specific Nutrients during the COVID-19 Pandemic: What Have We Learned over the Last Three Years?

Nutrients and diets have an important impact on our immune system and infection risk and a huge number of papers have been published dealing with various aspects of nutrition in relation to SARS-CoV-2 infection risk or COVID-19 severity. This narrative review aims to give an update on this association and tries to summarize some of the most important findings after three years of pandemic. The analysis of major studies and systematic reviews leads to the conclusion that a healthy plant-based diet reduces the risks for SARS-CoV-2 infection and especially COVID-19 severity. Regarding micronutrients, vitamin D is to the fore, but also zinc, vitamin C and, to some extent, selenium may play a role in COVID-19. Furthermore, omega-3-fatty acids with their anti-inflammatory effects also deserve attention. Therefore, a major aim of societal nutritional efforts in future should be to foster a high quality plant-based diet, which not only exerts beneficial effects on the immune system but also reduces the risk for non-communicable diseases such as type 2 diabetes or obesity which are also primary risk factors for worse COVID-19 outcomes. Another aim should be to focus on a good supply of critical immune-effective nutrients, such as vitamin D and zinc.

Vitamin C Deficiency in Blood Samples of COVID-19 Patients

Coronavirus disease 2019 (COVID-19) is the most notable pandemic of the modern era. A relationship between ascorbate (vitamin C) and COVID-19 severity is well known, whereas the role of other vitamins is less understood. The present study compared the blood levels of four vitamins in a cohort of COVID-19 patients with different severities and uninfected individuals. Serum concentrations of ascorbate, calcidiol, retinol, and α-tocopherol were measured in a cohort of 74 COVID-19 patients and 8 uninfected volunteers. The blood levels were statistically compared and additional co-morbidity factors were considered. COVID-19 patients had significantly lower plasma ascorbate levels than the controls (p-value < 0.001), and further stratification revealed that the controls had higher levels than fatal, critical, and severe COVID-19 cases (p-values < 0.001). However, no such trend was observed for calcidiol, retinol, or α-tocopherol (p-value ≥ 0.093). Survival analysis showed that plasma ascorbate below 11.4 µM was associated with a lengthy hospitalization and a high risk of death. The results indicated that COVID-19 cases had depleted blood ascorbate associated with poor medical conditions, confirming the role of this vitamin in the outcome of COVID-19 infection.

Fetal Brain Damage during Maternal COVID-19: Emerging Hypothesis, Mechanism, and Possible Mitigation through Maternal-Targeted Nutritional Supplementation

The recent outbreak of the novel Coronavirus (SARS-CoV-2 or CoV-2) pandemic in 2019 and the risk of CoV-2 infection during pregnancy led the scientific community to investigate the potential negative effects of Coronavirus infection on pregnancy outcomes and fetal development. In particular, as CoV-2 neurotropism has been demonstrated in adults, recent studies suggested a possible risk of fetal brain damage and fetal brain development impairment, with consequent psychiatric manifestations in offspring of mothers affected by COronaVIrus Disease (COVID) during pregnancy. Through the understanding of CoV-2's pathogenesis and the pathways responsible for cell damage, along with the available data about neurotropic virus attitudes, different strategies have been suggested to lower the risk of neurologic disease in newborns. In this regard, the role of nutrition in mitigating fetal damages related to oxidative stress and the inflammatory environment during viral infection has been investigated, and arginine, n3PUFA, vitamins B1 and B9, choline, and flavonoids were found to be promising in and out of pregnancy. The aim of this review is to provide an overview of the current knowledge on the mechanism of fetal brain damage and the impact of nutrition in reducing inflammation related to worse neurological outcomes in the context of CoV-2 infections during pregnancy.

Vitamins C and D and COVID-19 Susceptibility, Severity and Progression: An Evidence Based Systematic Review

Background and Objectives: Starting in early December 2019, the novel Coronavirus Disease (COVID-19) from infection with COVID-19 has caused a global pandemic. Many aspects of its pathogenesis and related clinical consequences are still unclear. Early diagnosis and dynamic monitoring of prognostic factors are essential to improve the ability to manage COVID-19 infection. This study aimed to provide an account of the role played by vitamins C and D on the onset, progression and severity of COVID-19. Clinical features and infection-related risk factors are also briefly discussed. Material and Methods: In March 2022, the main online databases were accessed. All the articles that investigate the possible role of vitamins C and D on COVID-19 susceptibility, severity and progression were considered. Results: The current evidence on vitamin C and D supplementation in patients with COVID-19 infection is inconsistent and controversial. In some studies, vitamins were used as coadjuvant of a formal experimental therapy, while in others as main treatment. Ethnicity and hospital setting (inpatient/outpatient) were also variable. Moreover, there was no consensus between studies in administration protocol: high heterogeneity in dosage, administration, and duration of the treatment were evident. Finally, some studies administered vitamins pre- and/or during COVID infection, in patients with different risk factors and infection severity. Conclusions: While waiting to develop a targeted, safe and effective therapy, it is important to investigate individual predisposition and proper disease management. Concluding, available data on the use of nutraceuticals in COVID-19 are inconsistent. However, there is a lack of evidence-based guidelines which recommend vitamin C and D supplementation in patients with COVID-19, and results from high quality randomised controlled trials (RCTs) are inconsistent. Current investigations so far are mostly observational, and include a relatively small sample size which can lead to biased results. Large-scale multicentre studies are therefore needed.

Serum Level of 4-Hydroxynonenal in Community-Acquired Pneumonia: A Potential Biomarker for Severity and Prognosis

Background

Four-hydroxynonenal (4-HNE) exerts a central role in the pathophysiological process of pulmonary diseases. The aim of this project was to evaluate the correlations between serum 4-HNE with severity and prognosis in patients with community-acquired pneumonia (CAP) by a prospective cohort study.

Materials and Methods

A total of 239 patients with CAP and healthy volunteers were recruited. Fasting blood was collected. Serum 4-HNE was measured with ELISA. Clinical characteristics and demographic information were obtained. The relationships between serum 4-HNE and clinical characteristics were evaluated through the Spearman or Pearson correlation coefficient. The associations of serum 4-HNE with severity and prognosis were estimated through logistic regression analysis.

Results

On admission, serum 4-HNE was upregulated in patients with CAP compared with healthy volunteers. Serum 4-HNE was gradually increased in line with CAP scores. Additionally, elderly patients with CAP were more prone to suffer from 4-HNE elevation. Moreover, serum 4-HNE was positively correlated with CAP severity scores. Meanwhile, the poor prognostic outcomes were tracked among patients with CAP. Higher serum 4-HNE on admission increased the risks of mechanical ventilation, vasoactive agent usage, and death in patients with CAP during hospitalization. The predictive powers for severity and death were increased in serum 4-HNE compared with CAP severity scores and inflammatory cytokines.

Conclusion

Serum 4-HNE on admission is positively correlated with the severity and poor prognosis among patients with CAP, indicating that 4-HNE participates in the pathophysiology of CAP. Serum 4-HNE may be used as an earlier biomarker for diagnosis and prognosis in patients with CAP.

Telmisartan ameliorates LPS-induced pneumonia in rats through regulation of the PPARγ/NF-κB pathway

Pneumonia is a common disorder of the respiratory system associated with inflammation. Telmisartan (TEL) has been reported to treat inflammatory-related diseases. The current study is aimed to make investigations for the possible role and action mechanism of TEL on lipopolysaccharide (LPS)-induced pneumonia rats. Forty male Sprague Dawley (SD) rats aged 8 weeks were assigned into four groups ad libitum: a control group received saline only, an experimental group received LPS, a group received TEL (5 mg/kg), followed by LPS treatment, and a group received TEL (10 mg/kg), followed by LPS treatment. LPS (2 mg/kg) and equal saline were administered intratracheally. TEL was orally administrated 5 days before LPS. After LPS treatment for 24 h, bronchoalveolar lavage fluid (BALF) and serum were collected for the analysis of cell counts and/or cytokines. Lung tissues were used to perform histological examination, assess oxidative stress levels, and determine the levels of PPARγ/NF-κB pathway-related proteins. Rats received LPS treatment exhibited high levels of lung wet/dry ratio, ALP, LDH, BALF polymorphonuclear leukocytes count, inflammatory cytokines, and oxidative stress. Meanwhile, LPS also resulted in severe interstitial edema and inflammatory cells infiltration. Interestingly, TEL by oral administration remarkably ameliorated the adverse effects on pneumonia rats caused by LPS. In addition, western blotting further revealed that TEL could activate PPARγ and repress NF-κB (p65). TEL is protective against pneumonia through inhibition of the inflammation and oxidative stress via the PPARγ/NF-κB pathway. This article is protected by copyright. All rights reserved.

Oxidative Stress and Hyper-Inflammation as Major Drivers of Severe COVID-19 and Long COVID: Implications for the Benefit of High-Dose Intravenous Vitamin C

Oxidative stress is a pivotal point in the pathophysiology of COVID-19 and presumably also in Long-COVID. Inflammation and oxidative stress are mutually reinforcing each other, thus contributing to the systemic hyperinflammatory state and coagulopathy which are cardinal pathological mechanisms of severe stages. COVID-19 patients, like other critically ill patients e.g. with pneumonia, very often show severe deficiency of the antioxidant vitamin C. So far, it has not been investigated how long this deficiency lasts or whether patients with long COVID symptoms also suffer from deficiencies. A vitamin C deficit has serious pathological consequences because vitamin C is one of the most effective antioxidants, but also co-factor of many enzymatic processes that affect the immune and nervous system, blood circulation and energy metabolism. Because of its anti-oxidative, anti-inflammatory, endothelial-restoring, and immunomodulatory effects the supportive intravenous (iv) use of supraphysiological doses has been investigated so far in 12 controlled or observational studies with altogether 1578 inpatients with COVID-19. In these studies an improved oxygenation, a decrease in inflammatory markers and a faster recovery were observed. In addition, early treatment with iv high dose vitamin C seems to reduce the risks of severe courses of the disease such as pneumonia and also mortality. Persistent inflammation, thrombosis and a dysregulated immune response (auto-immune phenomena and/or persistent viral load) seem to be major contributors to Long-COVID. Oxidative stress and inflammation are involved in the development and progression of fatigue and neuro-psychiatric symptoms in various diseases by disrupting tissue (e.g. autoantibodies), blood flow (e.g. immune thrombosis) and neurotransmitter metabolism (e.g. excitotoxicity). In oncological diseases, other viral infections and autoimmune diseases, which are often associated with fatigue, cognitive disorders, pain and depression similar to Long-COVID, iv high dose vitamin C was shown to significantly relieve these symptoms. Supportive iv vitamin C in acute COVID-19 might therefore reduce the risk of severe courses and also the development of Long-COVID.

Vitamin C for ≥ 5 days is associated with decreased hospital mortality in sepsis subgroups: a nationwide cohort study

Background

Previous randomized trials of vitamin C, hydrocortisone, and thiamine on sepsis were limited by short-term vitamin C administration, heterogeneous populations, and the failure to evaluate each component’s effect. The purpose of this study was to determine whether vitamin C alone for ≥ 5 days or in combination with corticosteroids and/or thiamine was associated with decreased mortality across the sepsis population and subpopulation.

Methods

Nationwide population-based study conducted using the Korean National Health Insurance Service database. A total of 384,282 adult patients with sepsis who were admitted to the intensive care unit were enrolled from January 2017 to December 2019. The primary outcome was hospital mortality, while the key secondary outcome was 90-day mortality.

Results

The mean [standard deviation] age was 69.0 [15.4] years; 57% were male; and 36,327 (9%) and 347,955 did and did not receive vitamin C, respectively. After propensity score matching, each group involved 36,327 patients. The hospital mortality was lower by − 0.9% in the treatment group (17.1% vs 18.0%; 95% confidence interval, − 1.3 to − 0.5%; p < 0.001), a significant but extremely small difference. However, mortality decreased greater in patients who received vitamin C for ≥ 5 days (vs 1–2 or 3–4 days) (15.8% vs 18.8% vs 18.3%; p < 0.001). Further, vitamin C was associated with a lower hospital mortality in patients with older age, multiple comorbidities, pneumonia, genitourinary infection, septic shock, and mechanical ventilation. Consistent findings were found for 90-day mortality. Moreover, vitamin C alone or in combination with thiamine was significantly associated with decreased hospital mortality.

Conclusions

Intravenous vitamin C of ≥ 5 days was significantly associated with decreased hospital and 90-day mortality in sepsis patients. Vitamin C combined with corticosteroids and/or thiamine in specific sepsis subgroups warrants further study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03872-3.

Vitamin C Intervention for Critical COVID-19: A Pragmatic Review of the Current Level of Evidence

Severe respiratory infections are characterized by elevated inflammation and generation of reactive oxygen species (ROS) which may lead to a decrease in antioxidants such as vitamin C and a higher requirement for the vitamin. Administration of intravenous vitamin C to patients with pneumonia and sepsis appears to decrease the severity of the disease and potentially improve survival rate. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes pneumonia, sepsis and acute respiratory distress syndrome (ARDS) in severe cases, and is referred to as coronavirus disease 2019 (COVID-19). Patients with COVID-19 infection also appear to have depleted vitamin C status and require additional supplementation of vitamin C during the acute phase of the disease. To date there have been 12 vitamin C and COVID-19 trials published, including five randomised controlled trials (RCTs) and seven retrospective cohort studies. The current level of evidence from the RCTs suggests that intravenous vitamin C intervention may improve oxygenation parameters, reduce inflammatory markers, decrease days in hospital and reduce mortality, particularly in the more severely ill patients. High doses of oral vitamin C supplementation may also improve the rate of recovery in less severe cases. No adverse events have been reported in published vitamin C clinical trials in COVID-19 patients. Upcoming findings from larger RCTs will provide additional evidence on vitamin supplementation in COVID-19 patients.

Neutrophils Isolated from Septic Patients Exhibit Elevated Uptake of Vitamin C and Normal Intracellular Concentrations despite a Low Vitamin C Milieu

Vitamin C (ascorbate) plays an important role in neutrophil function and is accumulated by the cells either directly via vitamin C transporters (SVCT) or indirectly following oxidation to dehydroascorbic acid. Septic patients are known to have significantly depleted plasma ascorbate status, but little is known about the ascorbate content of their circulating cells. Therefore, we assessed the ascorbate concentrations of plasma, leukocytes and erythrocytes from septic patients and compared these to healthy controls. Non-fasting blood samples were collected from healthy volunteers (n = 20) and critically ill patients with sepsis (n = 18). The ascorbate content of the plasma and isolated neutrophils and erythrocytes was measured using HPLC and plasma myeloperoxidase concentrations were determined using ELISA. Ex vivo uptake of ascorbate and dehydroascorbic acid by neutrophils from septic patients was also assessed. Neutrophils isolated from septic patients had comparable intracellular ascorbate content to healthy volunteers (0.33 vs. 0.35 nmol/10⁶ cells, p > 0.05), despite significantly lower plasma concentrations than the healthy controls (14 vs. 88 µmol/L, p < 0.001). In contrast, erythrocytes from septic patients had significantly lower intracellular ascorbate content than healthy controls (30 vs. 69 µmol/L, p = 0.002), although this was 2.2-fold higher than the matched plasma concentrations in the patients (p = 0.008). Higher concentrations of myeloperoxidase, a source of reactive oxygen species, were observed in the septic patients relative to healthy controls (194 vs. 14 mg/mL, p < 0.0001). In contrast to neutrophils from healthy volunteers, the neutrophils from septic patients demonstrated elevated uptake of extracellular ascorbate. Overall, neutrophils from septic patients exhibited comparable intracellular ascorbate content to those from healthy controls, despite the patients presenting with hypovitaminosis C. The mechanisms involved are currently uncertain, but could include increased generation of dehydroascorbic acid in septic patients, enhanced basal activation of their neutrophils or upregulation of their vitamin C transporters.

Vitamin supplementation as a potential adjunctive therapeutic approach for COVID-19: biological and clinical plausibility

The recent pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus Disease 2019 (COVID-19) has introduced itself into the human population in the 21st century after the coronavirus diseases SARS-CoV and Middle East respiratory syndrome (MERS-CoV). Major investigations are underway worldwide in the search for pharmaceutical interventions for COVID-19 and many agents are administered in off-label routes. Several cases are under study to check or restrict clinical manifestations of COVID-19. According to the fact that the efficacy of some micro-nutrients like vitamins is proven to treat or prevent infectious diseases because of their antimicrobial and immunomodulatory activity, the potential role of vitamins in the COVID-19 treatment or prevention must be considered.

Ex Vivo Evaluation of the Sepsis Triple Therapy High-Dose Vitamin C in Combination with Vitamin B1 and Hydrocortisone in a Human Peripheral Blood Mononuclear Cells (PBMCs) Model

Sepsis is an extremely complex clinical syndrome, usually involving an excessive inflammatory response including an overshooting cytokine release that damages tissue and organs of the patient. Due to the severity of this condition, it is estimated that over 11 million people die from sepsis each year. Despite intensive research in the field, there is still no specific therapy for sepsis. Many sepsis patients show a marked deficiency of vitamin C. 9 out of 10 sepsis patients have a hypovitaminosis C, and every third patient even shows a clinical deficiency in the scurvy range. In addition, low vitamin C levels of intensive care sepsis patients correlate with a higher need for vasopressors, higher Sequential Organ Failure Assessment (SOFA) scores, and increased mortality. Based on this observation and the conducted clinical trials using vitamin C as sepsis therapy in intensive care patients, the aim of the present ex vivo study was to evaluate the effects of high-dose vitamin C alone and in a triple combination supplemented with vitamin B1 (thiamine) and hydrocortisone on the lipopolysaccharide (LPS)-induced cytokine response in peripheral blood mononuclear cells (PBMCs) from healthy human donors. We found that all corticosteroid combinations strongly reduced the cytokine response on RNA- and protein levels, while high-dose vitamin C alone significantly diminished the PBMC mediated secretion of the cytokines interleukin (IL)-10, IL-23, and monocyte chemo-attractant protein (MCP-1), which mediate the inflammatory response. However, vitamin C showed no enhancing effect on the secretion of further cytokines studied. This data provides important insights into the possible immunomodulatory function of vitamin C in an ex vivo setting of human PBMCs and the modulation of their cytokine profile in the context of sepsis. Since vitamin C is a vital micronutrient, the restoration of physiologically adequate concentrations should be integrated into routine sepsis therapy, and the therapeutic effects of supraphysiological concentrations of vitamin C in sepsis patients should be further investigated in clinical trials.

Effects of Citrus Fruit Juices and Their Bioactive Components on Inflammation and Immunity: A Narrative Review

The immune system provides defence to the host against pathogenic organisms. A weak immune system increases susceptibility to infections and allows infections to become more severe. One component of the immune response is inflammation. Where inflammation is excessive or uncontrolled it can damage host tissues and cause pathology. Limitation of oxidative stress is one means of controlling inflammation. Citrus fruit juices are a particularly good source of vitamin C and folate, which both have roles in sustaining the integrity of immunological barriers and in supporting the function of many types of immune cell including phagocytes, natural killer cells, T-cells and B-cells. Vitamin C is an antioxidant and reduces aspects of the inflammatory response. Important bioactive polyphenols in citrus fruit juices include hesperidin, narirutin and naringin. Hesperidin is a glycoside of hesperetin while narirutin and naringin are glycosides of naringenin. Hesperidin, hesperetin, naringenin, naringin and narirutin have all been found to have anti-inflammatory effects in model systems, and human trials of hesperidin report reductions in inflammatory markers. In humans, orange juice was shown to limit the post-prandial inflammation induced by a high fat-high carbohydrate meal. Consuming orange juice daily for a period of weeks has been reported to reduce markers of inflammation, including C-reactive protein, as confirmed through a recent meta-analysis. A newly emerging topic is whether polyphenols from orange juice have direct anti-viral effects. In summary, micronutrients and other bioactives present in citrus fruit juices have established roles in controlling oxidative stress and inflammation and in supporting innate and acquired immune responses. Trials in humans demonstrate that orange juice reduces inflammation; its effects on innate and acquired immunity require further exploration in well-designed trials in appropriate population sub-groups such as older people.

Feasibility of Vitamin C in the Treatment of Post Viral Fatigue with Focus on Long COVID, Based on a Systematic Review of IV Vitamin C on Fatigue

Fatigue is common not only in cancer patients but also after viral and other infections. Effective treatment options are still very rare. Therefore, the present knowledge on the pathophysiology of fatigue and the potential positive impact of treatment with vitamin C is illustrated. Additionally, the effectiveness of high-dose IV vitamin C in fatigue resulting from various diseases was assessed by a systematic literature review in order to assess the feasibility of vitamin C in post-viral, especially in long COVID, fatigue. Nine clinical studies with 720 participants were identified. Three of the four controlled trials observed a significant decrease in fatigue scores in the vitamin C group compared to the control group. Four of the five observational or before-and-after studies observed a significant reduction in pre-post levels of fatigue. Attendant symptoms of fatigue such as sleep disturbances, lack of concentration, depression, and pain were also frequently alleviated. Oxidative stress, inflammation, and circulatory disorders, which are important contributors to fatigue, are also discussed in long COVID fatigue. Thus, the antioxidant, anti-inflammatory, endothelial-restoring, and immunomodulatory effects of high-dose IV vitamin C might be a suitable treatment option.

Vitamin C: From Bench to Bedside

Vitamin C (ascorbic acid) is a normal liver metabolite in most animals, with humans being a notable exception due to random genetic mutations that have occurred during our evolution [...].

Obesity, malnutrition, and trace element deficiency in the coronavirus disease (COVID-19) pandemic: An overview

The world is currently facing the coronavirus disease (COVID-19) pandemic which places great pressure on health care systems and workers, often presents with severe clinical features, and sometimes requires admission into intensive care units. Derangements in nutritional status, both for obesity and malnutrition, are relevant for the clinical outcome in acute illness. Systemic inflammation, immune system impairment, sarcopenia, and preexisting associated conditions, such as respiratory, cardiovascular, and metabolic diseases related to obesity, could act as crucial factors linking nutritional status and the course and outcome of COVID-19. Nevertheless, vitamins and trace elements play an essential role in modulating immune response and inflammatory status. Overall, evaluation of the patient's nutritional status is not negligible for its implications on susceptibility, course, severity, and responsiveness to therapies, in order to perform a tailored nutritional intervention as an integral part of the treatment of patients with COVID-19. The aim of this study was to review the current data on the relevance of nutritional status, including trace elements and vitamin status, in influencing the course and outcome of the disease 3 mo after the World Health Organization's declaration of COVID-19 as a pandemic.

Vitamin C-An Adjunctive Therapy for Respiratory Infection, Sepsis and COVID-19

There are limited proven therapies for COVID-19. Vitamin C's antioxidant, anti-inflammatory and immunomodulating effects make it a potential therapeutic candidate, both for the prevention and amelioration of COVID-19 infection, and as an adjunctive therapy in the critical care of COVID-19. This literature review focuses on vitamin C deficiency in respiratory infections, including COVID-19, and the mechanisms of action in infectious disease, including support of the stress response, its role in preventing and treating colds and pneumonia, and its role in treating sepsis and COVID-19. The evidence to date indicates that oral vitamin C (2-8 g/day) may reduce the incidence and duration of respiratory infections and intravenous vitamin C (6-24 g/day) has been shown to reduce mortality, intensive care unit (ICU) and hospital stays, and time on mechanical ventilation for severe respiratory infections. Further trials are urgently warranted. Given the favourable safety profile and low cost of vitamin C, and the frequency of vitamin C deficiency in respiratory infections, it may be worthwhile testing patients' vitamin C status and treating them accordingly with intravenous administration within ICUs and oral administration in hospitalised persons with COVID-19.

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 Emerging Role of Vitamin C in the Prevention and Treatment of COVID-19

Investigation into the role of vitamin C in the prevention and treatment of pneumonia and sepsis has been underway for many decades. This research has laid a strong foundation for translation of these findings into patients with severe coronavirus disease (COVID-19). Research has indicated that patients with pneumonia and sepsis have low vitamin C status and elevated oxidative stress. Administration of vitamin C to patients with pneumonia can decrease the severity and duration of the disease. Critically ill patients with sepsis require intravenous administration of gram amounts of the vitamin to normalize plasma levels, an intervention that some studies suggest reduces mortality. The vitamin has pleiotropic physiological functions, many of which are relevant to COVID-19. These include its antioxidant, anti-inflammatory, antithrombotic and immuno-modulatory functions. Preliminary observational studies indicate low vitamin C status in critically ill patients with COVID-19. There are currently a number of randomized controlled trials (RCTs) registered globally that are assessing intravenous vitamin C monotherapy in patients with COVID-19. Since hypovitaminosis C and deficiency are common in low-middle-income settings, and many of the risk factors for vitamin C deficiency overlap with COVID-19 risk factors, it is possible that trials carried out in populations with chronic hypovitaminosis C may show greater efficacy. This is particularly relevant for the global research effort since COVID-19 is disproportionately affecting low-middle-income countries and low-income groups globally. One small trial from China has finished early and the findings are currently under peer review. There was significantly decreased mortality in the more severely ill patients who received vitamin C intervention. The upcoming findings from the larger RCTs currently underway will provide more definitive evidence. Optimization of the intervention protocols in future trials, e.g., earlier and sustained administration, is warranted to potentially improve its efficacy. Due to the excellent safety profile, low cost, and potential for rapid upscaling of production, administration of vitamin C to patients with hypovitaminosis C and severe respiratory infections, e.g., COVID-19, appears warranted.

Factors Affecting Vitamin C Status and Prevalence of Deficiency: A Global Health Perspective

A recent review of global vitamin C status has indicated a high prevalence of deficiency, particularly in low- and middle-income countries, as well as in specific subgroups within high-income countries. Here, we provide a narrative review of potential factors influencing vitamin C status globally. The in vivo status of vitamin C is primarily affected by dietary intake and supplement use, with those who supplement having a higher mean status and a lower prevalence of deficiency. Dietary intake can be influenced by cultural aspects such as traditional cooking practices and staple foods, with many staple foods, such as grains, contributing negligible vitamin C to the diet. Environmental factors can also affect vitamin C intake and status; these include geographic region, season, and climate, as well as pollution, the latter partly due to enhanced oxidative stress. Demographic factors such as sex, age, and race are known to affect vitamin C status, as do socioeconomic factors such as deprivation, education and social class, and institutionalization. Various health aspects can affect vitamin C status; these include body weight, pregnancy and lactation, genetic variants, smoking, and disease states, including severe infections as well as various noncommunicable diseases such as cardiovascular disease and cancer. Some of these factors have changed over time; therefore, we also explore if vitamin C status has shown temporal changes. Overall, there are numerous factors that can affect vitamin C status to different extents in various regions of the world. Many of these factors are not taken into consideration during the setting of global dietary intake recommendations for vitamin C.

Patients Undergoing Myeloablative Chemotherapy and Hematopoietic Stem Cell Transplantation Exhibit Depleted Vitamin C Status in Association with Febrile Neutropenia

Patients undergoing myeloablative chemotherapy and hematopoietic stem cell transplantation (HSCT) experience profound neutropenia and vulnerability to infection. Previous research has indicated that patients with infections have depleted vitamin C status. In this study, we recruited 38 patients with hematopoietic cancer who were undergoing conditioning chemotherapy and HSCT. Blood samples were collected prior to transplantation, at one week, two weeks and four weeks following transplantation. Vitamin C status and biomarkers of inflammation (C-reactive protein) and oxidative stress (protein carbonyls and thiobarbituric acid reactive substances) were assessed in association with febrile neutropenia. The vitamin C status of the study participants decreased from 44 ± 7 µmol/L to 29 ± 5 µmol/L by week one (p = 0.001) and 19 ± 6 µmol/L by week two (p < 0.001), by which time all of the participants had undergone a febrile episode. By week four, vitamin C status had increased to 37 ± 10 µmol/L (p = 0.1). Pre-transplantation, the cohort comprised 19% with hypovitaminosis C (i.e., <23 µmol/L) and 8% with deficiency (i.e., <11 µmol/L). At week one, those with hypovitaminosis C had increased to 38%, and at week two, 72% had hypovitaminosis C, and 34% had outright deficiency. C-reactive protein concentrations increased from 3.5 ± 1.8 mg/L to 20 ± 11 mg/L at week one (p = 0.002), and 119 ± 25 mg/L at week two (p < 0.001), corresponding to the development of febrile neutropenia in the patients. By week four, these values had dropped to 17 ± 8 mg/L (p < 0.001). There was a significant inverse correlation between C-reactive protein concentrations and vitamin C status (r = -0.424, p < 0.001). Lipid oxidation (thiobarbituric acid reactive substances (TBARS)) increased significantly from 2.0 ± 0.3 µmol/L at baseline to 3.3 ± 0.6 µmol/L by week one (p < 0.001), and remained elevated at week two (p = 0.003), returning to baseline concentrations by week four (p = 0.3). Overall, the lowest mean vitamin C values (recorded at week two) corresponded with the highest mean C-reactive protein values and lowest mean neutrophil counts. Thus, depleted vitamin C status in the HSCT patients coincides with febrile neutropenia and elevated inflammation and oxidative stress.