Safety of vitamin C in sepsis: a neglected topic

Association between vitamin C intake and thyroid function among U.S. adults: a population-based study

Background

Although some evidence suggests a role for vitamin C intake in thyroid diseases, the complex interplay between vitamin C intake and thyroid function remains incompletely understood. The objective of this study was to explore the relationship between vitamin C intake and serum thyroid function in the United States adults.

Methods

A total of 5,878 participants from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2012 were included in this study. Weighted multivariate linear regression models, subgroup analyses, and interaction terms were used to assess the association between vitamin C intake, evaluated as a continuous and categorical variable, and thyroid function. Additionally, restricted cubic spline (RCS) regression was employed to assess any nonlinear relationship that may exist between vitamin C intake and thyroid function.

Results

After adjusting for covariates, our research found a significant inverse correlation between vitamin C intake and total thyroxine (TT4) (β= -0.182, P= 0.006). Using subgroup analyses, the association was more pronounced among subjects with lower alcohol consumption(β= -0.151, P=0.013, P for interaction = 0.043). In RCS regression, the correlation between vitamin C and TT4 exhibited a distinct reversed L-shaped curve pattern in total participants (P for nonlinear = 0.005) and male adults (P for nonlinear = 0.014). Additionally, we found an inverted U-shaped curve pattern in the relationship between vitamin C intake and FT4 (P for nonlinear = 0.029), while an U-shaped curve relationship was observed between vitamin C consumption and the FT3/FT4 ratio (P for nonlinear = 0.026).

Conclusion

The findings of our study have illustrated a notable correlation between vitamin C intake and thyroid function. A high level of vitamin C intake is associated with a decreased in TT4 levels among American adults, and the association was more pronounced among subjects with lower alcohol consumption. Furthermore, our analysis revealed a nonlinear correlation between the intake of vitamin C and the levels of TT4, FT4, and FT3/FT4 ratio. Our findings support the rationale for making food-based dietary recommendations and maybe provide guidance for diet guidelines with thyroid dysfunction to a certain extent in the future.

Vitamin C for all?

PURPOSE OF REVIEW

Vitamin C can be a potential adjunctive treatment option for critically ill individuals due to its pleiotropic effects as electron donor in many enzymatic reactions throughout the body. Recently, several important randomized controlled trials (RCTs) investigating vitamin C in critically ill patients have been published.

RECENT FINDINGS

Two recent large RCTs administering high-dose vitamin C to patients with sepsis and COVID-19 showed signs of harm. Though performed at high standard, these trials had several limitations. Recent studies in cardiac surgery and burns showed decreased cardiac enzymes and improved clinical outcomes after cardiac surgery, and decreased fluid requirements, reduced wound healing time and in-hospital mortality after burns. Vitamin C may hold benefit in the management of other ischemia/reperfusion injury populations, including postcardiac arrest patients and after solid organ transplantation. Currently, covering basal vitamin C requirements during critical illness is recommended, though the exact dose remains to be determined.

SUMMARY

Future work should address optimal vitamin C timing, since early versus late drug administration are likely distinct, and duration of therapy, where withdrawal-induced injury is possible. Additionally accurate assessment of body stores with determination of individual vitamin requirements is crucial to ascertain patient and subgroups most likely to benefit from vitamin C.

Cell signaling pathways based on vitamin C and their application in cancer therapy

Vitamin C, a small organic molecule, is widely found in fruits and vegetables and is an essential nutrient in the human body. Vitamin C is closely associated with some human diseases such as cancer. Many studies have shown that high doses of vitamin C have anti-tumor ability and can target tumor cells in multiple targets. This review will describe vitamin C absorption and its function in cancer treatment. We will review the cellular signaling pathways associated with vitamin C against tumors depending on the different anti-cancer mechanisms. Based on this, we will further describe some applications of the use of vitamin C for cancer treatment in preclinical and clinical trials and the possible adverse events that can occur. Finally, this review also assesses the prospective advantages of vitamin C in oncology treatment and clinical applications.

Vitamin C and vitamin D3 alleviate metabolic-associated fatty liver disease by regulating the gut microbiota and bile acid metabolism via the gut-liver axis

Background: Previous studies have demonstrated that both vitamin C (VC) and vitamin D3 (VD3) have therapeutic potential against metabolic disorders, including obesity, diabetes, and metabolic-associated fatty liver disease (MAFLD). However, it is unclear whether VC supplementation is associated with improving the intestinal flora and regulating the metabolism of bile acids via the gut-liver axis in MAFLD. There is still no direct comparison or combination study of these two vitamins on these effects.

Methods: In this study, we employed biochemical, histological, 16S rDNA-based microbiological, non-targeted liver metabolomic, and quantitative real-time polymerase chain reaction analyses to explore the intervening effect and mechanism of VC and VD3 on MAFLD by using a high-fat diet (HFD)-induced obese mouse model.

Results: Treatment of mice with VC and VD3 efficiently reversed the characteristics of MAFLD, such as obesity, dyslipidemia, insulin resistance, hepatic steatosis, and inflammation. VC and VD3 showed similar beneficial effects as mentioned above in HFD-induced obese mice. Interestingly, VC and VD3 reshaped the gut microbiota composition; improved gut barrier integrity; ameliorated oxidative stress and inflammation in the gut-liver axis; inhibited bile acid salt reflux-related ASBT; activated bile acid synthesis-related CYP7A1, bile acid receptor FXR, and bile acid transportation-related BSEP in the gut-liver axis; and improved bile secretion, thus decreasing the expression of FAS in the liver and efficiently ameliorating MAFLD in mice.

Conclusion: Together, the results indicate that the anti-MAFLD activities of VC and VD3 are linked to improved gut-liver interactions via regulation of the gut microbiota and bile acid metabolism, and they may therefore prove useful in treating MAFLD clinically.

Early administration of Vitamin C in patients with sepsis or septic shock in emergency departments: A multicenter, double blinded, randomized controlled trial: The C-EASIE trial protocol

BACKGROUND

Sepsis is a potentially life-threatening condition characterized by a deregulated body's response to infection causing injury to its own tissues and organs. Sepsis is the primary cause of death from infection. If not recognized and treated timely, it can evolve within minutes/hours to septic shock. Sepsis is associated with an acute deficiency of Vitamin C. Despite the proof-of-concept of the benefit of administering Vitamin C in patients with sepsis or septic shock, Vitamin C administration is not yet current practice.

OBJECTIVE

To investigate the potential benefit of early administration of high doses of Vitamin C in addition to standard of care in patients with sepsis or septic shock.

METHODS

This phase 3b multi-center trial is conducted in 8 hospitals throughout Belgium. In total 300 patients will be randomly assigned to one of two groups in a 1:1 allocation ratio. The intervention group will receive 1.5 g Vitamin C 4 times a day during 4 days, started within 6 hours after admission. The primary outcome is the average post-baseline patient SOFA score.

CONCLUSION

This trial will determine whether the early administration of Vitamin C in patients with sepsis or septic shock can lead to a more rapid solution of shock and less deterioration from sepsis to septic shock, hereby reducing morbidity and mortality as well as the length of hospital stay in this patient population.

TRIAL REGISTRATION

The C-EASIE trial has been registered on the ClinicalTrials.gov website on 10 February 2021 with registration number NCT04747795.

TRIAL SPONSOR

UZ Leuven (sponsor's reference S63213).

Effects of Oral Vitamin C Supplementation on Liver Health and Associated Parameters in Patients With Non-Alcoholic Fatty Liver Disease: A Randomized Clinical Trial

Non-alcoholic fatty liver disease (NAFLD) is now recognized as the most prevalent hepatic disorder worldwide, and an unhealthy lifestyle is the leading risk factor for its occurrence. Vitamin C (VC) has been suggested to protect NAFLD, whereas evidence from randomized controlled trials (RCTs) is sparse. In this study, we aimed to investigate the potential benefits of VC supplementation daily on liver health and associated parameters in patients with NAFLD. In this double-blind, RCT, 84 patients with NAFLD, aged 18-60 years old, were assigned to 12 weeks of oral treatment with either low (250 mg/day, n = 26), medium (1,000 mg/day, n = 30), or high (2,000 mg/day, n = 28) doses of VC supplements. After the intervention, the Medium group had a more significant decrease in aspartate aminotransferase [Medium, -5.00 (-10.25, -1.75) vs. High, -2.50 (-7.75, 0.00), P = 0.02] and alanine aminotransferase [Medium, -8.00 (-18.00, -1.75) vs. High, -3.50 (-13.75, 4.25), P = 0.05; Medium vs. Low, -3.00 (-9.00, 5.50), P = 0.031]. The levels of other indicators of liver health, such as gamma-glutamyl transferase, alkaline phosphatase, total bilirubin, and direct bilirubin were decreased after the intervention but comparable among the three groups and so did the parameters of glucose metabolism, such as fasting insulin, fasting glucose, and homeostasis model assessment for insulin resistance. The plasma level of VC in patients and total adiponectin and high molecular weight (HMW) adiponectin levels were also elevated but not in a dose-dependent manner. Meanwhile, analysis of fecal microbiota composition showed an increase in the alpha diversity (Abundance-based Coverage Estimator (ACE), Shannon, chao1, and Simpson) both in the Low and the Medium groups. A total of 12 weeks of VC supplementation, especially 1,000 mg/day, improved liver health and glucose metabolism in patients with NAFLD. The elevated plasma levels of VC, total and HMW adiponectin, and the improvement of intestinal microbiota may have made some contributions.

Efficacy and Safety of Parenteral High-Dose Vitamin C Therapy in Pediatric Patients: A Scoping Review

OBJECTIVES

Recently, several adult trials have investigated the potential benefit of high-dose vitamin C therapy in critically ill patients. In pediatric patients, little is known on the efficacy, safety, and risk of high-dose vitamin C therapy. We aimed to review the efficacy and potential harm associated with high-dose vitamin C treatment.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane Library, and National Institute of Health Clinical Trials Register.

STUDY SELECTION

We included studies in neonatal and pediatric patients who received IV or intra-arterial high-dose vitamin C (ascorbic acid) defined as greater than or equal to 75 mg/kg/d.

DATA EXTRACTION

Two independent investigators screened articles and extracted data.

DATA SYNTHESIS

We found 1,364 articles, assessed 193 full texts for eligibility, and identified 12 eligible studies. These studies included 855 patients, with 194 receiving high-dose vitamin C. The age of patients who received high-dose vitamin C ranged from 2 hours after delivery to 8.4 years (median 2.4 yr), and the vitamin C dose ranged from 100 to 1,500 mg/kg/d (median 260.5 mg/kg/d). Four studies were double-blind randomized controlled trials, and no clinical efficacy outcome was reported in favor of or against vitamin C. Furthermore, no adverse event or signal of harm was reported with high-dose vitamin C.

CONCLUSIONS

In 12 studies with 194 children treated with parenteral high-dose vitamin C, there was no evidence of clinical efficacy or inferior clinical outcomes in double-blind randomized controlled trials, and no reported harmful effects. These findings justify further investigations of this treatment in children.

Витамин С при критических состояниях: от эксперимента к клинике (часть 2)

Витамин С (аскорбиновая кислота) играет важную физиологическую роль в многочисленных метаболических функциях. Он также является кофактором в синтезе важных веществ, в частности катехоламинов и вазопрессина. Снижение уровня аскорбиновой кислоты отмечено при различных заболеваниях и часто сопровождает тяжелое состояние больного. Целью этой статьи является обзор современных представлений о применении высоких доз витамина С при критических состояниях у хирургических больных. Для поиска литературных источников использовалась база Medline на платформе Pubmed по ключевым словам: витамин С, сепсис, шок, травма, ожоги.

Vitamin C and kidney transplantation: Nutritional status, potential efficacy, safety, and interactions

BACKGROUND AND AIM

There are several observational and interventional studies regarding the advantages of sufficient serum levels of vitamin C and the evaluation of the effects of vitamin C supplementation post kidney transplantation. These studies have been put together to investigate the role of vitamin C post-kidney transplantation and make suggestions for designing future studies based on the use of vitamin C supplements or nutritional interventions among these patients.

METHODS

This narrative review was done by searching in the Embase, PubMed, and SCOPUS databases.

RESULTS

The results are presented in several sections as follows; nutritional status, potential protective effects, safety concerns, and medications/laboratory tests interactions of vitamin C.

CONCLUSIONS

Kidney transplant recipients are prone to vitamin C deficiency, which is related to higher mortality based on several long-term observational studies. Vitamin C supplementation improves endothelial function and creatinine clearance. Vitamin C is considered as a safe supplement, however, side effects such as kidney stones, pro-oxidant effect, hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency, impact on lymphocytic activity, acid-base disturbance, and increased sodium load following its administration have been reported. Interaction of vitamin C and cyclosporine is the most important interaction with post-renal transplant medications. Vitamin C also interferes with creatinine assay using Jaffe and enzymatic methods.

Pilot trial of high-dose vitamin C in critically ill COVID-19 patients

BACKGROUND

Few specific medications have been proven effective for the treatment of patients with severe coronavirus disease 2019 (COVID-19). Here, we tested whether high-dose vitamin C infusion was effective for severe COVID-19.

METHODS

This randomized, controlled, clinical trial was performed at 3 hospitals in Hubei, China. Patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the ICU were randomly assigned in as 1:1 ratio to either the high-dose intravenous vitamin C (HDIVC) or the placebo. HDIVC group received 12 g of vitamin C/50 ml every 12 h for 7 days at a rate of 12 ml/hour, and the placebo group received bacteriostatic water for injection in the same way within 48 h of arrival to ICU. The primary outcome was invasive mechanical ventilation-free days in 28 days (IMVFD28). Secondary outcomes were 28-day mortality, organ failure (Sequential Organ Failure Assessment (SOFA) score), and inflammation progression (interleukin-6).

RESULTS

Only 56 critical COVID-19 patients were ultimately recruited due to the early control of the outbreak. There was no difference in IMVFD28 between two groups (26.0 [9.0-28.0] in HDIVC vs 22.0 [8.50-28.0] in control, p = 0.57). HDIVC failed to reduce 28-day mortality (P = 0.27). During the 7-day treatment period, patients in the HDIVC group had a steady rise in the PaO2/FiO2 (day 7: 229 vs. 151 mmHg, 95% CI 33 to 122, P = 0.01), which was not observed in the control group. IL-6 in the HDIVC group was lower than that in the control group (19.42 vs. 158.00; 95% CI -301.72 to -29.79; P = 0.04) on day 7.

CONCLUSION

This pilot trial showed that HDIVC failed to improve IMVFD28, but might show a potential signal of benefit in oxygenation for critically ill patients with COVID-19 improving PaO2/FiO2 even though.

Procyanidin B1 promotes in vitro maturation of pig oocytes by reducing oxidative stress

Oxidative stress negatively affects the in vitro maturation (IVM) of oocytes. Procyanidin B1 (PB1) is a natural polyphenolic compound that has antioxidant properties. In this study, we investigated the effect of PB1 supplementation during IVM of porcine oocytes. Treatment with 100 μM PB1 significantly increased the MII oocytes rate (p <0.05), the parthenogenetic (PA) blastocyst rate (p <0.01) and the total cell number in the PA blastocyst (p < 0.01) which were cultured in regular in vitro culture (IVC) medium. The PA blastocyst rate of regular MII oocytes activated and cultured in IVC medium supplemented with 100 and 150 μM PB1 significantly increased compared with control (p < 0.01 and p < 0.05). We also evaluated the reactive oxygen species (ROS) levels, mitochondrial membrane potential (Δψm) levels, glutathione (GSH) levels, and apoptotic levels in MII oocytes and cumulus cells following 100 μM PB1 treatment. The results showed that the PB1 supplementation decreased ROS production and apoptotic levels. In addition, PB1 was found to increase Δψm levels and GSH levels. In conclusion, PB1 inhibited apoptosis of oocytes and cumulus cells by reducing oxidative stress. Moreover, PB1 improved the quality of oocytes and promoted PA embryo development. Taken together, our results suggest that PB1 is a promising antioxidant additive for IVM of oocytes.

Prophylactic and therapeutic effects of different doses of vitamin C on high-fat-diet-induced non-alcoholic fatty liver disease in mice

Epidemiological studies support the association between inadequate vitamin C (Vc) intake and non-alcoholic fatty liver disease (NAFLD). However, the intervention dose of Vc, and the prophylactic and therapeutic effects on NAFLD are unclear. This study aimed to investigate the prophylactic and therapeutic effects of low (LVc), medium (MVc) and high (HVc) doses of Vc on NAFLD. C57BL/6 mice were randomly assigned to prophylactic groups (mice received a high-fat diet (HFD) concomitant with different doses of Vc) and therapeutic groups (HFD-induced NAFLD mice treated with different doses of Vc). Results showed that prophylactic LVc and MVc administration reduced the risk of NAFLD development in HFD-fed mice, as evidenced by significantly lowered body weight, perirenal adipose tissue mass, and steatosis, whereas prophylactic HVc administration did not prevent HFD-induced NAFLD development. Furthermore, therapeutic MVc administration significantly ameliorated HFD-induced increase in body weight, perirenal adipose tissue mass and steatosis, whereas therapeutic LVc and HVc administration did not ameliorate NAFLD symptoms. In fact, therapeutic HVc administration significantly increased body weight, perirenal adipose tissue mass, and lobular inflammation. Moreover, prophylactic LVc administration was more effective than therapeutic LVc administration as evidenced by significantly lower body weight, perirenal adipose tissue mass, steatosis, ballooned hepatocytes, and lobular inflammation in prophylactic LVc administration. The same trends were observed between prophylactic HVc administration and therapeutic HVc administration. In addition, all Vc-administered mice exhibited low blood glucose, triglycerides and homeostasis model assessment of insulin resistance values and high adiponectin levels compared to HFD-fed mice. Our study suggested that MVc was beneficial for HFD-induced NAFLD prophylaxis and therapy. LVc prevented HFD-induced NAFLD development, while HVc for NAFLD management was risky. This study offers valuable insight into the effect of various Vc doses on NAFLD management.

Intravenous high-dose vitamin C for the treatment of severe COVID-19: study protocol for a multicentre randomised controlled trial

INTRODUCTION

The rapid worldwide spread of COVID-19 has caused a global health crisis. To date, symptomatic supportive care has been the most common treatment. It has been reported that the mechanism of COVID-19 is related to cytokine storms and subsequent immunogenic damage, especially damage to the endothelium and alveolar membrane. Vitamin C (VC), also known as L-ascorbic acid, has been shown to have antimicrobial and immunomodulatory properties. A high dose of intravenous VC (HIVC) was proven to block several key components of cytokine storms, and HIVC showed safety and varying degrees of efficacy in clinical trials conducted on patients with bacterial-induced sepsis and acute respiratory distress syndrome (ARDS). Therefore, we hypothesise that HIVC could be added to the treatment of ARDS and multiorgan dysfunction related to COVID-19.

METHODS AND ANALYSIS

The investigators designed a multicentre prospective randomised placebo-controlled trial that is planned to recruit 308 adults diagnosed with COVID-19 and transferred into the intensive care unit. Participants will randomly receive HIVC diluted in sterile water or placebo for 7 days once enrolled. Patients with a history of VC allergy, end-stage pulmonary disease, advanced malignancy or glucose-6-phosphate dehydrogenase deficiency will be excluded. The primary outcome is ventilation-free days within 28 observational days. This is one of the first clinical trials applying HIVC to treat COVID-19, and it will provide credible efficacy and safety data. We predict that HIVC could suppress cytokine storms caused by COVID-19, help improve pulmonary function and reduce the risk of ARDS of COVID-19.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of Zhongnan Hospital of Wuhan University (identifiers: Clinical Ethical Approval No. 2020001). Findings of the trial will be disseminated through peer-reviewed journals and scientific conferences.

TRIAL REGISTRATION NUMBER

NCT04264533.

Evaluation of the effect of high dose intravenous vitamin C on delayed allograft function in deceased donor kidney transplantation: a preliminary report

Background

Delayed graft function (DGF) can affect short- and long-term allograft outcomes in kidney transplant recipients. One of the pathophysiological pathways in the occurrence of DGF is ischemia-reperfusion injury (IRI). High dose intravenous vitamin C has proven efficacy in decreasing IRI consequences. Accordingly, we designed this study to assess the effect of high dose intravenous vitamin C on the incidence and duration of DGF.

Methods

This is a pilot, single-center, double-blinded, randomized, placebo-controlled trial. In the treatment group, kidney transplant recipients received vitamin C infusion at the dose of 70 mg/kg diluted in 0.45% saline, and in another study arm, only the diluent solution was administered. Data regarding allograft function and other clinical information was recorded.

Results

This preliminary study on 19 patients (9 cases in the vitamin C and 10 cases in the placebo group) showed that after administration of single, high dose vitamin C the incidence of DGF was not significantly different between the groups, but the duration of DGF was substantially shorter in the vitamin C group than the placebo group (7.33 ± 5.68 versus 19.66 ± 0.57 days; P = 0.02). Acute rejection episodes were more seen in the vitamin C group than in the placebo group. Although this data was not statistically significant (P = 0.37), it led to the termination of the study.

Conclusion

A high dose of intravenous vitamin C before allograft implantation was effective in decreasing DGF duration but not DGF incidence.

Trial registration

The trial was registered in the Iranian registry of clinical trials encoded IRCT20100111003043N13 on June 24, 2019.

Harm of IV High-Dose Vitamin C Therapy in Adult Patients: A Scoping Review

OBJECTIVES

The potential harm associated with the use of IV vitamin C has not been systematically assessed. We aimed to review the available evidence on harm related to such treatment.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane Library, National Institute of Health Clinical Trials Register, and World Health Organization International Clinical Trials Registry Platform.

STUDY SELECTION

We included studies in adult population that reported harm related to IV high-dose vitamin C which we defined as greater than or equal to 6 g/d, greater than or equal to 75 mg/kg/d, or greater than or equal to 3 g/m/d.

DATA EXTRACTION

Two independent investigators screened records and extracted data.

DATA SYNTHESIS

We identified 8,149 reports, of which 650 full text were assessed for eligibility, leaving 74 eligible studies. In these studies, 2,801 participants received high-dose vitamin C at a median (interquartile range) dose of 22.5 g/d (8.25-63.75 g/d), 455 mg/kg/d (260-925 mg/kg/d), or 70 g/m/d (50-90 g/m/d); and 932 or more adverse events were reported. Among nine double-blind randomized controlled trials (2,310 patients), adverse events were reported in three studies with an event rate per patient for high-dose vitamin C identical to placebo group in one study (0.1 [1/10] vs 0.1 [1/10]), numerically lower in one study (0.80 [672/839] vs 0.82 [709/869]), and numerically higher in one study (0.33 [24/73] vs 0.23 [17/74]). Six double-blind randomized controlled trials reported no adverse event in either group. Five cases of oxalate nephropathy, five cases of hypernatremia, three cases of hemolysis in glucose-6-phosphate dehydrogenase deficiency patients, two cases of glucometer error, and one case of kidney stones were also reported overall.

CONCLUSIONS

There is no consistent evidence that IV high-dose vitamin C therapy is more harmful than placebo in double-blind randomized controlled trials. However, reports of oxalate nephropathy, hypernatremia, glucometer error, and hemolysis in glucose-6-phosphate dehydrogenase deficiency patients warrant specific monitoring.

Treating sepsis with vitamin C, thiamine, and hydrocortisone: Exploring the quest for the magic elixir

The administration of ascorbic acid (vitamin C) alone or in combination with thiamine (vitamin B1) and corticosteroids (VCTS) has recently been hypothesized to improve hemodynamics, end-organ function, and may even increase survival in critically ill patients. There are several clinical studies that have investigated the use of vitamin C alone or VCTS in patients with sepsis and septic shock or are ongoing. Some of these studies have demonstrated its safety and potential benefit in septic patients. However, many questions remain regarding the optimal dosing regimens and plasma concentrations, timing of administration, and adverse effects of vitamin C and thiamine. These questions exist because the bulk of research regarding the efficacy of vitamin C alone or in combination with thiamine and corticosteroids in sepsis is limited to a few randomized controlled trials, retrospective before-and-after studies, and case reports. Thus, although the underlying rationale and mechanistic pathways of vitamin C and thiamine in sepsis have been well described, the clinical impact of the VCTS regimen is complex and remains to be determined. This review aims to explore the current evidence and potential benefits and adverse effects of the VCTS regimen for the treatment of sepsis.

Vitamin C: an essential "stress hormone" during sepsis

The stress response is a preserved evolutionary response that functions to enhance the survival of the species. In mammals, the stress response is characterized by activation of the HPA axis and sympathoadrenal system (SAS) as well as the increased synthesis and secretion of vitamin C. Cortisol, catecholamines, and vitamin C act synergistically to increase hemodynamic reserve, maintain immune function and protect the host against excessive oxidant injury. Humans (and anthropoid apes) have lost the ability to synthesize vitamin C and therefore have an impaired stress response. The inability to produce vitamin C has serious implications in septic humans. Treatment with vitamin C appears to restore the stress response and improve the survival of stressed humans.