Vitamin C status of an outpatient population

Scurvy: A Rare Disease or a Rare Diagnosis?

Introduction

Scurvy, the disease state caused by ascorbic acid deficiency, was once an extremely common disease but is now thought to be a rare disease in postmodern societies. Physicians are not trained to consider scurvy as a possible diagnosis in patients at risk; rather, it is considered a rare diagnosis to add to a differential for completeness's sake.

Methods

We sought to describe the scorbutic patients seen by one physician during a busy academic emergency medicine career. Case series of patients seen by one physician between 1993 and 2023 at five academic teaching hospitals with Emergency Departments (EDs) in the mid-Eastern United States. Presenting signs and symptoms, known scurvy risk factors, Vitamin C levels, clinical course, and outcome for each patient are described.

Results

There were 14 presentations by 12 patients diagnosed with scurvy who were initially evaluated in the ED between 1993 and 2023. Each patient had a known risk factor for inadequate Vitamin C intake. All had clinical findings suggestive of scurvy and all but one had a subnormal serum Vitamin C level detected on serum samples sent from the ED.

Conclusion

The detection of 12 cases of scurvy by one physician over a three-decade period highlights the importance of screening for scurvy in at-risk populations and generates the hypothesis that scurvy is not a rare disease but rather a rare diagnosis. This research hypothesis should be investigated in further studies.

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 ).

The Forgotten Disease in the 21st Century: Scurvy Outbreak in Hawassa Central Prison, Hawassa, Sidama, Southern Ethiopia, 2023

Background

Dietary deficiencies in vitamin C lead to scurvy, an uncommon disease of nutritional deficiency in contemporary clinical practice. The inability of humans to synthesize vitamin C necessitates the regular consumption of vitamin C containing fruits, vegetables, or tablets.

Objective

To report a series of cases that came to HUCSH from May 25th up to the 18th of July, 2023, and to describe clinical features of scurvy from an observational study of on-site prison investigation.

Methods

A descriptive analysis of a case series of ten patients admitted to HUCSH between May 25th and July 18th, 2023, and on-site observational study of 67 patients over one month. A structured questionnaire was used to collect data, and SPSS version 25 was used for analysis.

Results

From the case series, all of the ten patients had either unilateral or bilateral leg swelling or pain as common compliant and all of them were male prisoners with mean age of 25.6±5.33 years and following admission, the hemoglobin value increased to 7.1±1.34 g/dL with treatment from 4.6±1.88 g/dL. From observational study of the prison, 67 cases were identified based on unilateral or bilateral leg swelling and/or pain, which was the presenting feature in the cluster of cases seen at HUCSH. The mean age was 23.57±6.4 years, and each patient got therapeutic doses of ascorbic acid 500mg PO daily using directly observed therapy and follow-up visit was after two and four weeks of ascorbic acid initiation and all patients showed significant improvement.

Conclusion

For clinicians in modern medicine, there should be a high index of suspicion for scurvy as a possible differential diagnosis when a patient presents with leg swelling in high-risk population, such as prisoners. Health-care providers in prison clinics need to be alert to such forgotten yet life-costly disease in resource constrained prison clinics.

Fatal Epileptic Seizures in Mice Having Compromised Glutathione and Ascorbic Acid Biosynthesis

Reduced glutathione (GSH) and ascorbic acid (AA) are the two most abundant low-molecular-weight antioxidants in mammalian tissues. Gclm^KO knockout mice lack the gene encoding the modifier subunit of the rate-limiting enzyme in GSH biosynthesis; Gclm^KO mice exhibit 10-40% of normal tissue GSH levels and show no overt phenotype. Gulo^KO knockout mice, lacking a functional Gulo gene encoding L-gulono-γ-lactone oxidase, cannot synthesize AA and depend on dietary ascorbic acid for survival. To elucidate functional crosstalk between GSH and AA in vivo, we generated the Gclm^KO/Gulo^KO double-knockout (DKO) mouse. DKO mice exhibited spontaneous epileptic seizures, proceeding to death between postnatal day (PND)14 and PND23. Histologically, DKO mice displayed neuronal loss and glial proliferation in the neocortex and hippocampus. Epileptic seizures and brain pathology in young DKO mice could be prevented with AA supplementation in drinking water (1 g/L). Remarkably, in AA-rescued adult DKO mice, the removal of AA supplementation for 2-3 weeks resulted in similar, but more severe, neocortex and hippocampal pathology and seizures, with death occurring between 12 and 21 days later. These results provide direct evidence for an indispensable, yet underappreciated, role for the interplay between GSH and AA in normal brain function and neuronal health. We speculate that the functional crosstalk between GSH and AA plays an important role in regulating glutamatergic neurotransmission and in protecting against excitotoxicity-induced brain damage.

Ascorbic Acid Deficiency Prevalence and Associated Cognitive Impairment in Alcohol Detoxification Inpatients: A Pilot Study

Malnutrition has been reported in alcohol use disorder patients as having a possible influence on cognitive function. The aim of this study was to analyse the prevalence of ascorbic acid (AA) deficiency in inpatients admitted for alcohol detoxification and the associated factors, including cognitive impairment in the early period of abstinence. A retrospective chart review was conducted. The AA level was categorised into three groups: deficiency (AAD) (<2 mg/L), insufficiency (AAI) (2–5 mg/L) and normal level. The cognitive impairment was screened using the Montreal Cognitive Assessment (MoCA). Ninety-six patients were included (74 men; mean age 49.1 years (±11.5)). Twenty-seven AAD (28.1%) and twenty-two AAI (22.9%) were observed. In multivariate analysis, risk factors for AAD versus normal AA level were men (OR 17.8, 95%CI (1.63–194)), compensated cirrhosis (OR 9.35, 95%CI (1.60–54.6)) and street homelessness (OR 5.76, 95%CI (1.24–26.8) versus personal housing). The MoCA score was available for 53 patients (mean MoCA score: 25.7 (±3.3)). In multivariate analysis, the natural logarithm of AA (β = 1.18, p = 0.037) and sedative use disorder (β = −2.77, p = 0.046) were associated with the MoCA score. AAD and AAI are frequent in inpatients admitted for alcohol detoxification. A low level of AA was associated with cognitive impairment in the early period of abstinence.

Vitamin C supplementation for prevention and treatment of pneumonia

BACKGROUND

According to the Global Burden of Disease Study 2015, lower respiratory tract infection is the leading cause of infectious disease death, and the fifth most common cause of death overall. Vitamin C has a role in modulating resistance to infectious agents, therefore vitamin C supplementation may be important in preventing and treating pneumonia.

OBJECTIVES

To assess the impact of vitamin C supplementation to prevent and treat pneumonia in children and adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PubMed, CINAHL, LILACS, Web of Science, and two trials registers to 4 March 2020. We also checked references to identify additional studies. We did not apply any publication status or language filters.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (studies using allocation methods that are not random, e.g. date of birth, medical record number) assessing the role of vitamin C supplementation in the prevention and treatment of pneumonia in children and adults compared to control or placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included five studies in the review and identified two ongoing studies. The five included studies involved a total of 2655 participants; two studies were RCTs and three were quasi-RCTs. The included studies were conducted in one high-income country (USA) and three lower-middle-income countries (Bangladesh and Pakistan). Three studies were conducted in hospital inpatient settings, one in school, and one in a military training centre. Three studies included children under five years of age, one study included school-aged children, and one study included adult participants. Two studies assessed the effect of vitamin C supplementation for pneumonia prevention; and three studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment. For pneumonia prevention, the included studies provided supplementation in doses of 1 g daily for 14 weeks, 2 g daily for 8 weeks, and 2 g daily for 14 weeks. For pneumonia treatment, the included studies provided vitamin C supplementation in doses of 125 mg daily and 200 mg daily until the symptoms resolved or discharge, as an adjunct to the pneumonia treatment. Overall, the included studies were judged to be at either high or unclear risk of bias for random sequence generation, allocation concealment, and blinding; and the evidence certainty was very low. Two studies assessed the effect of vitamin C supplementation for pneumonia prevention; we judged the certainty of the evidence as very low. We are uncertain about the effect of vitamin C supplementation on pneumonia incidence and adverse events (urticaria). None of the included studies reported other primary outcomes (pneumonia prevalence and mortality) or any of the secondary outcomes. Three studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment; we judged the certainty of the evidence as very low. We are uncertain of the effect of vitamin C supplementation on duration of illness and hospitalisation. None of the included studies reported other primary or secondary outcomes.

AUTHORS' CONCLUSIONS

Due to the small number of included studies and very low certainty of the existing evidence, we are uncertain of the effect of vitamin C supplementation for the prevention and treatment of pneumonia. Further good-quality studies are required to assess the role of vitamin C supplementation in the prevention and treatment of pneumonia.

Vitamin C Deficiency in the Young Brain-Findings from Experimental Animal Models

Severe and long-term vitamin C deficiency can lead to fatal scurvy, which is fortunately considered rare today. However, a moderate state of vitamin C (vitC) deficiency (hypovitaminosis C)-defined as a plasma concentration below 23 μM-is estimated to affect up to 10% of the population in the Western world, albeit clinical hallmarks in addition to scurvy have not been linked to vitC deficiency. The brain maintains a high vitC content and uniquely high levels during deficiency, supporting vitC's importance in the brain. Actions include both antioxidant and co-factor functions, rendering vitamin C deficiency likely to affect several targets in the brain, and it could be particularly significant during development where a high cellular metabolism and an immature antioxidant system might increase sensitivity. However, investigations of a non-scorbutic state of vitC deficiency and effects on the developing young brain are scarce. This narrative review provides a comprehensive overview of the complex mechanisms that regulate vitC homeostasis in vivo and in the brain in particular. Functions of vitC in the brain and the potential consequences of deficiency during brain development are highlighted, based primarily on findings from experimental animal models. Perspectives for future investigations of vitC are outlined.

Vitamin C supplementation for prevention and treatment of pneumonia

BACKGROUND

According to the Global Burden of Disease Study 2015, lower respiratory tract infection is the leading cause of infectious disease death, and the fifth most common cause of death overall. Vitamin C has a role in modulating resistance to infectious agents, therefore vitamin C supplementation may be important in preventing and treating pneumonia.

OBJECTIVES

To assess the impact of vitamin C supplementation to prevent and treat pneumonia in children and adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PubMed, CINAHL, LILACS, Web of Science, and two trials registers to 4 March 2020. We also checked references to identify additional studies. We did not apply any publication status or language filters.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs (studies using allocation methods that are not random, e.g. date of birth, medical record number) assessing the role of vitamin C supplementation in the prevention and treatment of pneumonia in children and adults compared to control or placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included seven studies in the review and identified two ongoing studies. The seven included studies involved a total of 2774 participants; five studies were RCTs and two were quasi-RCTs. The included studies were conducted in high-income countries (UK, USA and Chile) and lower-middle-income countries (Bangladesh and Pakistan). Four studies were conducted in hospital inpatient settings, two in schools, and one in a military training centre. Three studies included children under five years of age, two school-aged children, one adult participants, and one older participants aged 60 to 90 years. Two studies assessed the effect of vitamin C supplementation for pneumonia prevention; four studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment; and one study assessed the role of vitamin C for both prevention and treatment of pneumonia. For pneumonia prevention, the included studies provided supplementation in doses of 500 mg daily for 14 weeks, 2 g daily for 8 weeks, and 2 g daily for 12 weeks. For pneumonia treatment, the included studies provided vitamin C supplementation in doses of 125 mg daily (until discharge), 200 mg for 4 weeks, and 200 mg until discharge, as an adjunct to the pneumonia treatment. We assessed the included studies as at overall either high or unclear risk of bias for random sequence generation, allocation concealment, and blinding. We judged the quality of the evidence as very low. Three studies assessed the effect of vitamin C supplementation for pneumonia prevention; we judged the quality of the evidence as very low. We are uncertain about the effect of vitamin C supplementation on pneumonia incidence (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.06 to 3.61; 2 studies, 736 participants; I² = 75%; very low-quality evidence) and adverse events (urticaria) (RR 3.11, 95% CI 0.13 to 76.03; 1 study, 674 participants; very low-quality evidence). No included studies reported our other primary outcomes (pneumonia prevalence and mortality) or any of our secondary outcomes. Five studies assessed the effect of vitamin C supplementation as an adjunct to pneumonia treatment; we judged the quality of the evidence as very low. One study reported a decrease in the duration of illness in the vitamin C supplementation group (3.4 days ± 2.54) compared to the control group (4.5 days ± 2.35), and one study reported a decrease in number of days required for improvement in oxygen saturation (1.03 days ± 0.16 versus 1.14 days ± 1.0) and respiratory rate (3.61 days ± 1.50 versus 4.04 days ± 1.62) in the vitamin C supplementation group compared to the control group. We are uncertain of the effect of vitamin C supplementation on mortality due to pneumonia (RR 0.21, 95% CI 0.03 to 1.66; 1 study, 57 participants; very low-quality evidence). One study reported that the mean duration of hospital stay was 6.75 days amongst children in the vitamin C supplementation group and 7.75 days in the control group; another study reported a lower mean duration of hospital stay in the vitamin C supplementation group compared to the control group (109.55 hours ± 27.89 versus 130.64 hours ± 41.76).

AUTHORS' CONCLUSIONS

Due to the small number of included studies and very low quality of the existing evidence, we are uncertain of the effect of vitamin C supplementation for the prevention and treatment of pneumonia. Further good-quality studies are required to assess the role of vitamin C supplementation in the prevention and treatment of pneumonia.

Assessment of the Stability of Supraphysiological Ascorbate in Human Blood: Appropriate Handling of Samples from Clinical Trials for Measurements of Pharmacological Ascorbate

Based on encouraging results from several early-phase clinical trials, there is renewed interest in the use of pharmacological ascorbate (i.e., intravenous administration resulting in >≈10 mM plasma ascorbate concentrations) in combination with standard-of-care cancer treatments including radiation and/or chemotherapy. Under normal, healthy physiological conditions, humans maintain plasma ascorbate concentrations in the range of 40-80 lM. However, in vivo antitumor activity requires supraphysiological plasma concentrations on the order of ≈20 mM. The stability of ascorbate in whole blood has been well studied. The goal of this work was to determine the appropriate handling methods of blood samples, after treatment with pharmacological ascorbate, which allow for the optimal measurement of ascorbate in plasma for dosing verification. Our findings indicate that ascorbate concentrations (mM) are relatively stable in whole blood collected in sodium heparin tubes and stored on ice (or at 4°C) for up to 24 h. After 24 h, ascorbate levels in plasma are relatively stable at 4°C for up to 72 h. At -20°C, plasma concentrations are relatively stable for 2-3 weeks, while at -80°C, ascorbate concentrations in plasma are stable for at least one month. In contrast, patient samples showed better stability when stored as whole blood compared to plasma at 4°C but increasing hemolysis over time may significantly skew ascorbate measurements. Additionally, patient samples can be reliably stored as plasma at -20°C for up to three weeks in either a frost-containing or frost-free environment. This information can guide the collection, processing and storage of clinical samples after pharmacological ascorbate infusions amenable to multi-center clinical trials.

Alcohol Withdrawal: Possible Risk of Latent Scurvy Appearing as Tiredness: A STROBE-Compliant Study

Background

Little is known about the prevalence of vitamin C deficiency in the population of individuals who are withdrawing from alcohol, and about possible consequences of latent scurvy. The aim of this study was to evaluate the prevalence of vitamin C deficiency in patients who were withdrawing from alcohol, its correlation with latent scurvy (mainly tiredness and weakness) and the change in the latter symptoms at 3 months after oral vitamin C supplementation.

Methods

A total of 47 patients (33 males, 14 females) who volunteered to undertake alcohol detoxification were included prospectively between January 2014 and November 2016. Determination of vitamin C blood levels was performed, and selected clinical signs of latent scurvy were recorded in a structured questionnaire. The decrease of tiredness after vitamin C supplementation was also studied 3 months after the inclusion of patients who had no other explanation for their weakness.

Results

About 57.44% of the patients were affected by vitamin C deficiency (< 11.4 mol/L). Less than one-third (29.70%) had a normal plasma vitamin C level. There was a clear correlation between decreased vitamin C levels and the presence of tiredness (P = 0.003) and no correlation between gum inflammation or purpura (P = 0.97 and 0.44 respectively). After 3 months of alcohol withdrawal and vitamin C supplementation, 89% of the patients reported a decrease of tiredness.

Conclusions

Vitamin C deficiency is prevalent in patients undertaking alcohol detoxification. Patients with this vitamin deficiency status often suffer from tiredness, which may be symptoms of latent scurvy. Even if tiredness is a highly nonspecific symptom, presence of fatigue should draw attention and the vitamin C level should be determined. Our preliminary data suggest that vitamin C supplementation, may decrease fatigue and improve patient’s quality of life. This last evolution needs to be confirmed by a double-blind randomized study.

Intravenous vitamin C in the treatment of allergies: an interim subgroup analysis of a long-term observational study

Objective Oxidative stress appears to be a key factor in the pathogenesis of allergic diseases and a potential therapeutic target in allergy treatment. Allergic diseases are reportedly associated with reduced plasma levels of ascorbate, which is a key physiological antioxidant. Ascorbate prevents excessive inflammation without reducing the defensive capacity of the immune system. Methods An interim analysis of a multicenter, prospective, observational study was conducted to investigate the change in disease-specific and nonspecific symptoms (fatigue, sleep disorders, depression, and lack of mental concentration) during adjuvant treatment with intravenous vitamin C (Pascorbin®; Pascoe, Giessen, Germany) in 71 patients with allergy-related respiratory or cutaneous indications. Results Between the start and end of treatment, the mean sum score of three disease-specific symptoms decreased significantly by 4.71 points and that of four nonspecific symptoms decreased significantly by 4.84 points. More than 50% of patients took no other allergy-related medication besides vitamin C. Conclusions Our observations suggest that treatment with intravenous high-dose vitamin C reduces allergy-related symptoms. Our observations form a basis for planning a randomized controlled clinical trial to obtain more definitive evidence of the clinical relevance of our findings. We also obtained evidence of ascorbate deficiency in allergy-related diseases.

TRIAL REGISTRATION

Clinical Trials NCT02422901.

Appropriate Handling, Processing and Analysis of Blood Samples Is Essential to Avoid Oxidation of Vitamin C to Dehydroascorbic Acid

Vitamin C (ascorbate) is the major water-soluble antioxidant in plasma and its oxidation to dehydroascorbic acid (DHA) has been proposed as a marker of oxidative stress in vivo. However, controversy exists in the literature around the amount of DHA detected in blood samples collected from various patient cohorts. In this study, we report on DHA concentrations in a selection of different clinical cohorts (diabetes, pneumonia, cancer, and critically ill). All clinical samples were collected into EDTA anticoagulant tubes and processed at 4 °C prior to storage at −80 °C for subsequent analysis by HPLC with electrochemical detection. We also investigated the effects of different handling and processing conditions on short-term and long-term ascorbate and DHA stability in vitro and in whole blood and plasma samples. These conditions included metal chelation, anticoagulants (EDTA and heparin), and processing temperatures (ice, 4 °C and room temperature). Analysis of our clinical cohorts indicated very low to negligible DHA concentrations. Samples exhibiting haemolysis contained significantly higher concentrations of DHA. Metal chelation inhibited oxidation of vitamin C in vitro, confirming the involvement of contaminating metal ions. Although EDTA is an effective metal chelator, complexes with transition metal ions are still redox active, thus its use as an anticoagulant can facilitate metal ion-dependent oxidation of vitamin C in whole blood and plasma. Handling and processing blood samples on ice (or at 4 °C) delayed oxidation of vitamin C by a number of hours. A review of the literature regarding DHA concentrations in clinical cohorts highlighted the fact that studies using colourimetric or fluorometric assays reported significantly higher concentrations of DHA compared to those using HPLC with electrochemical detection. In conclusion, careful handling and processing of samples, combined with appropriate analysis, is crucial for accurate determination of ascorbate and DHA in clinical samples.

Vitamin C Depletion and All-Cause Mortality in Renal Transplant Recipients

Vitamin C may reduce inflammation and is inversely associated with mortality in the general population. We investigated the association of plasma vitamin C with all-cause mortality in renal transplant recipients (RTR); and whether this association would be mediated by inflammatory biomarkers. Vitamin C, high sensitive C-reactive protein (hs-CRP), soluble intercellular cell adhesion molecule 1 (sICAM-1), and soluble vascular cell adhesion molecule 1 (sVCAM-1) were measured in a cohort of 598 RTR. Cox regression analyses were used to analyze the association between vitamin C depletion (≤28 µmol/L; 22% of RTR) and mortality. Mediation analyses were performed according to Preacher and Hayes's procedure. At a median follow-up of 7.0 (6.2-7.5) years, 131 (21%) patients died. Vitamin C depletion was univariately associated with almost two-fold higher risk of mortality (Hazard ratio (HR) 1.95; 95% confidence interval (95%CI) 1.35-2.81, p < 0.001). This association remained independent of potential confounders (HR 1.74; 95%CI 1.18-2.57, p = 0.005). Hs-CRP, sICAM-1, sVCAM-1 and a composite score of inflammatory biomarkers mediated 16, 17, 15, and 32% of the association, respectively. Vitamin C depletion is frequent and independently associated with almost two-fold higher risk of mortality in RTR. It may be hypothesized that the beneficial effect of vitamin C at least partly occurs through decreasing inflammation.

Perioperative ascorbic acid supplementation does not reduce the incidence of postoperative atrial fibrillation in on-pump coronary artery bypass graft patients

BACKGROUND

Atrial fibrillation is the most common arrhythmia following cardiac surgery. It is associated with increased hemodynamic instability, systemic embolization, and complications linked to anticoagulant therapy. Oxidative stress and consequent electrophysiological remodeling have been proposed as a cause of postoperative atrial fibrillation. Ascorbic acid supplementation was suggested as a novel and effective preventive agent. The aim of this study was to evaluate the capability of ascorbic acid to reduce the incidence of postoperative atrial fibrillation in coronary artery bypass grafting (CABG) patients.

METHODS

A prospective randomized single-center trial was conducted in patients scheduled for an elective on-pump CABG surgery. Subjects in the ascorbic acid group received 2g of ascorbic acid 24h and 2h before the surgery and 1g twice a day for five days after the surgery. Postoperatively, the patients were monitored for atrial fibrillation and other complications.

RESULTS

The ascorbic acid group consisted of 52 patients and the control group included 53 patients. The groups were well matched for baseline demographics, preoperative medications, comorbidities, and had similar intraoperative characteristics. The incidence of atrial fibrillation in the ascorbic acid group was 13.5% and 18.9% in the control group (p=0.314). No difference was found between groups in the time of occurrence of atrial fibrillation (3.71±1.89 vs. 2.91±1.58 days after the surgery; p=0.342). There was also no difference in the other observed postoperative complications.

CONCLUSIONS

The results of this study do not support the effectiveness of ascorbic acid supplementation in reducing the incidence of postoperative atrial fibrillation in elective on-pump CABG patients.

Maternal vitamin C deficiency during pregnancy results in transient fetal and placental growth retardation in guinea pigs

PURPOSE

Recently, we reported that preferential maternal-fetal vitamin C (vitC) transport across the placenta is likely to be impaired by prolonged maternal vitC deficiency. Maintenance of a basal maternal vitC supply at the expense of the fetus may impair fetal development; however, the knowledge of vitC's impact on intrauterine development is sparse. The aim of this study was to explore the effect of maternal vitC status on fetal and placental development in guinea pigs.

METHODS

Twenty pregnant Dunkin Hartley guinea pigs were randomized into four groups to receive diets either sufficient (918 mg/kg CTRL) or deficient (100 mg/kg DEF) in vitC. Cesarean sections at gestational day (GD) 45 or 56 allowed for fetal and placental measurements.

RESULTS

At GD45, body, brain and placental weights were significantly reduced in DEF pups compared with CTRL (p < 0.05, p < 0.001 and p < 0.05, respectively). DEF plasma vitC levels were ~6% of those of CTRL (p < 0.0001), and the fetal/maternal plasma vitC ratio was significantly reduced at GD56 in the DEF animals compared with controls (p = 0.035). Placental vitC levels were reduced in DEF animals (p < 0.0001) and the ascorbate oxidation ratio and glutathione elevated compared with controls (p < 0.0001).

CONCLUSIONS

Although no clinical differences between CTRL and DEF pups were observed at GD56, the present data suggest that vitC plays a role in early fetal development. Although no clinical differences between CTRL and DEF pups were observed at GD56, the present data suggest that vitC plays a role in early fetal development. Low maternal vitC intake during pregnancy may compromise maternal weight gain, placental function and intrauterine development.

Does vitamin C deficiency affect cognitive development and function?

Vitamin C is a pivotal antioxidant in the brain and has been reported to have numerous functions, including reactive oxygen species scavenging, neuromodulation, and involvement in angiogenesis. Absence of vitamin C in the brain has been shown to be detrimental to survival in newborn SVCT2(−/−) mice and perinatal deficiency have shown to reduce hippocampal volume and neuron number and cause decreased spatial cognition in guinea pigs, suggesting that maternal vitamin C deficiency could have severe consequences for the offspring. Furthermore, vitamin C deficiency has been proposed to play a role in age-related cognitive decline and in stroke risk and severity. The present review discusses the available literature on effects of vitamin C deficiency on the developing and aging brain with particular focus on in vivo experimentation and clinical studies.

Selected physiologic variables are weakly to moderately associated with 29 biomarkers of diet and nutrition, NHANES 2003-2006

The physiologic status of an individual may influence biomarkers of nutritional status. To help researchers with planning studies and interpreting data, we assessed the associations between common physiologic variables (fasting, inflammation, renal function, and pregnancy) and 29 biomarkers of diet and nutrition measured in blood or urine in a representative sample of the adult U.S. population (aged ≥ 20 y; pregnancy variable and iron indicators limited to women aged 20-49 y) participating in NHANES 2003-2006. We compared simple linear regression (model 1) with multiple linear regression [model 2, controlling for age, sex, race-ethnicity, smoking, supplement use, and the physiologic factors (and urine creatinine for urine biomarkers)] and report significant findings from model 2. Not being fasted was positively associated with most water-soluble vitamins (WSVs) and related metabolites (RMs). Some WSV, fat-soluble vitamin (FSV) and micronutrient (MN), and phytoestrogen concentrations were lower in the presence of inflammation (C-reactive protein ≥ 5 mg/L), whereas fatty acids and most iron indicators were higher. Most WSVs and RMs were higher when renal function was impaired [estimated glomerular filtration rate <60 mL/(min · 1.73 m(2))]. Most WSV, FSV and MN, and fatty acid concentrations were higher in pregnant compared with nonpregnant women, but vitamins A and B-12 and most iron indicators were lower. The estimated changes in biomarker concentrations with different physiologic status were mostly small to moderate (≤ 25%) and generally similar between models; renal function, however, showed several large differences for WSV and RM concentrations. This descriptive analysis of associations between physiologic variables and a large number of nutritional biomarkers showed that controlling for demographic variables, smoking, and supplement use generally did not change the interpretation of bivariate results. The analysis serves as a useful basis for more complex future research.

L-ascorbic Acid: a multifunctional molecule supporting plant growth and development

L-Ascorbic acid (vitamin C) is as essential to plants as it is to animals. Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Ascorbic acid regulates cell division and growth and is involved in signal transduction. In contrast to the single pathway responsible for ascorbic acid biosynthesis in animals, plants use multiple pathways to synthesize ascorbic acid, perhaps reflecting the importance of this molecule to plant health. Given the importance of ascorbic acid to human nutrition, several technologies have been developed to increase the ascorbic acid content of plants through the manipulation of biosynthetic or recycling pathways. This paper provides an overview of these approaches as well as the consequences that changes in ascorbic acid content have on plant growth and function. Discussed is the capacity of plants to tolerate changes in ascorbic acid content. The many functions that ascorbic acid serves in plants, however, will require highly targeted approaches to improve their nutritional quality without compromising their health.

Behavioral and monoamine changes following severe vitamin C deficiency

Severe vitamin C deficiency (ascorbic acid; AA) was induced in gulo-/- mice incapable of synthesizing their own AA. A number of behavioral measures were studied before and during the deprivation period, including a scorbutic period, during which weight loss was observed in the mice. Mice were then resuscitated with AA supplements. During the scorbutic period, gulo-/- mice showed decreased voluntary locomotor activity, diminished physical strength, and increased preference for a highly palatable sucrose reward. These behaviors all returned to control levels following resuscitation. Altered trial times in subordinate mice in the tube test for social dominance in the AA-deprived mice persisted following resuscitation and may signify a depressive-like behavior in these mice. Biochemical analyses were undertaken following a second deprivation period. AA deficiency was accompanied by decreased blood glucose levels, oxidative damage to lipids and proteins in the cortex, and decreases in dopamine and serotonin metabolites in both the cortex and striatum. Given the reasonably high proportions of the population that do not consume sufficient AA in the diet, these data have important implications for physical and psychological function in the general population.

A critical review of vitamin C for the prevention of age-related cognitive decline and Alzheimer's disease

Antioxidants in the diet have long been thought to confer some level of protection against the oxidative damage that is involved in the pathology of Alzheimer's disease as well as general cognitive decline in normal aging. Nevertheless, support for this hypothesis in the literature is equivocal. In the case of vitamin C (ascorbic acid) in particular, lack of consideration of some of the specific features of vitamin C metabolism has led to studies in which classification of participants according to vitamin C status is inaccurate, and the absence of critical information precludes the drawing of appropriate conclusions. Vitamin C levels in plasma are not always reported, and estimated daily intake from food diaries may not be accurate or reflect actual plasma values. The ability to transport ingested vitamin C from the intestines into blood is limited by the saturable sodium-dependent vitamin C transporter (SVCT1) and thus very high intakes and the use of supplements are often erroneously considered to be of greater benefit that they really are. The current review documents differences among the studies in terms of vitamin C status of participants. Overall, there is a large body of evidence that maintaining healthy vitamin C levels can have a protective function against age-related cognitive decline and Alzheimer's disease, but avoiding vitamin C deficiency is likely to be more beneficial than taking supplements on top of a normal, healthy diet.

Differential regulation of the ascorbic acid transporter SVCT2 during development and in response to ascorbic acid depletion

The sodium-dependent vitamin C transporter-2 (SVCT2) is the only ascorbic acid (ASC) transporter significantly expressed in brain. It is required for life and is critical during brain development to supply adequate levels of ASC. To assess SVCT2 function in the developing brain, we studied time-dependent SVCT2 mRNA and protein expression in mouse brain, using liver as a comparison tissue because it is the site of ASC synthesis. We found that SVCT2 expression followed an inverse relationship with ASC levels in the developing brain. In cortex and cerebellum, ASC levels were high throughout late embryonic stages and early post-natal stages and decreased with age, whereas SVCT2 mRNA and protein levels were low in embryos and increased with age. A different response was observed for liver, in which ASC levels and SVCT2 expression were both low throughout embryogenesis and increased post-natally. To determine whether low intracellular ASC might be capable of driving SVCT2 expression, we depleted ASC by diet in adult mice unable to synthesize ASC. We observed that SVCT2 mRNA and protein were not affected by ASC depletion in brain cortex, but SVCT2 protein expression was increased by ASC depletion in the cerebellum and liver. The results suggest that expression of the SVCT2 is differentially regulated during embryonic development and in adulthood.

Retinal hemorrhage in abusive head trauma

Retinal hemorrhage is a cardinal manifestation of abusive head trauma. Over the 30 years since the recognition of this association, multiple streams of research, including clinical, postmortem, animal, mechanical, and finite element studies, have created a robust understanding of the clinical features, diagnostic importance, differential diagnosis, and pathophysiology of this finding. The importance of describing the hemorrhages adequately is paramount in ensuring accurate and complete differential diagnosis. Challenges remain in developing models that adequately replicate the forces required to cause retinal hemorrhage in children. Although questions, such as the effect of increased intracranial pressure, hypoxia, and impact, are still raised (particularly in court), clinicians can confidently rely on a large and solid evidence base when assessing the implications of retinal hemorrhage in children with concern of possible child abuse.

Low vitamin C and increased oxidative stress and cell death in mice that lack the sodium-dependent vitamin C transporter SVCT2

The sodium-dependent vitamin C transporter (SVCT2) is responsible for the transport of vitamin C into cells in multiple organs, from either the blood or the cerebrospinal fluid. Mice null for SVCT2 (SVCT2(-/-)) do not survive past birth but the cause of death has not yet been ascertained. After mating of SVCT2(+/-) males and SVCT2(+/-) females, fewer SVCT2(-/-) and SVCT2(+/-) progeny were observed than would be expected according to Mendelian ratios. Vitamin C levels in SVCT2(-/-), SVCT2(+/-), and SVCT2(+/+) were genotype-dependent. SVCT2(-/-) fetuses had significantly lower vitamin C levels than littermates in placenta, cortex, and lung, but not in liver (the site of vitamin C synthesis). Low vitamin C levels in placenta and cortex were associated with elevations in several markers of oxidative stress: malondialdehyde, isoketals, F(2)-isoprostanes, and F(4)-neuroprostanes. Oxidative stress was not elevated in fetal SVCT2(-/-) lung tissue despite low vitamin C levels. In addition to the expected severe hemorrhage in cortex, we also found hemorrhage in the brain stem, which was accompanied by cell loss. We found evidence of increased apoptosis in SVCT2(-/-) mice and disruption of the basement membrane in fetal brain. Together these data show that SVCT2 is critical for maintaining vitamin C levels in fetal and placental tissues and that the lack of SVCT2, and the resulting low vitamin C levels, results in fetal death and, in SVCT2(-/-) mice that survive the gestation period, in oxidative stress and cell death.

Low ascorbic acid and increased oxidative stress in gulo(-/-) mice during development

Vitamin C (ascorbic acid, AA) depletion during prenatal and postnatal development can lead to oxidative stress in the developing brain and other organs. Such damage may lead to irreversible effects on later brain function. We studied the relationship between AA deficiency and oxidative stress during development in gulonolactone oxidase (gulo) knockout mice that are unable to synthesize their own ascorbic acid. Heterozygous gulo(+/-) mice can synthesize AA and typically have similar tissue levels to wild-type mice. Gulo(+/-) dams were mated with gulo(+/-) males to provide offspring of each possible genotype. Overall, embryonic day 20 (E20) and postnatal day 1 (P1) pups were protected against oxidative stress by sufficient AA transfer during pregnancy. On postnatal day 10 (P10) AA levels were dramatically lower in liver and cerebellum in gulo(-/-) mice and malondialdehyde (MDA) levels were significantly increased. In postnatal day 18 pups (P18) AA levels decreased further in gulo(-/-) mice and oxidative stress was observed in the accompanying elevations in MDA in liver, and F(2)-isoprostanes in cortex. Further, total glutathione levels were higher in gulo(-/-) mice in cortex, cerebellum and liver, indicating that a compensatory antioxidant system was activated. These data show a direct relationship between AA level and oxidative stress in the gulo(-/-) mice. They reinforce the critical role of ascorbic acid in preventing oxidative stress in the developing brain in animals that, like humans, cannot synthesize their own AA.

Vitamin C distribution and retention in the mouse brain

Vitamin C (VC) is a crucial antioxidant in the brain. To assess whether different brain regions vary in their sensitivity to oxidative stress induced by VC depletion, we used the gulonolactone oxidase (gulo) knockout mouse. This mouse, like humans, cannot synthesize VC and thus its tissue VC levels can be varied by dietary VC intake. Gulo knockout mice were fed drinking water containing standard (0.33g/L), low (0.033g/L) or zero (0g/L) VC supplementation levels. After 4weeks, mice were sacrificed and different brain regions removed for assay of VC and malondialdehyde, a marker of lipid peroxidation. Compared to age-matched wild-type controls, the cerebellum, olfactory bulbs and frontal cortex had the highest VC content, whereas the pons and spinal chord had the lowest. However, in mice that did not receive VC, area differences were no longer significant as all values trended towards zero. Malondialdehyde increased in the cortex as VC supplementation was decreased. The same changes were not observed in the cerebellum or pons, suggesting that cortex is more susceptible to oxidative damage from low VC. These results suggest enhanced susceptibility of the cortex to oxidative stress induced by low VC compared to other brain regions.

Scurvy in hospitalized elderly patients

OBJECTIVES

The aim of this study was to systematically screen hospitalized elderly patients for clinical symptoms of scurvy and to confirm the diagnosis with biological measures.

SETTINGS

Geriatric acute care ward.

MEASUREMENTS

Scurvy symptoms (one or more among perifollicular hyperkeratosis, petechiae or bruises, haemorrhagic features caused by venous puncture, severe gingivitis). We compared associated diseases, nutritional status, need for assistance for feeding, serum albumin, transthyretin, B9 and B12 vitamins, iron status and Serum Ascorbic Acid Level (SAAL) and outcome (in-hospital mortality) between scurvy and scurvy free patients.

RESULTS

18 patients with clinical symptoms of scurvy (scurvy group) were identified out of 145 consecutive patients (12%). They were compared to 23 consecutive control patients with no clinical symptoms of scurvy (scurvy-free group). SAAL was significantly lower (1.09 +/- 1.06 vs 4.87 +/- 4.2 mg x L-1, p < .001) and vitamin C deficiency more frequent (94 vs 30 %, p < .001) in the scurvy group. Moreover, in scurvy group, coronary heart disease (39 vs 9 %, p=.028), need for assistance for feeding (56 vs 13 %, p=.006) and in-hospital deaths (44 vs 9 %, p=.012) were more frequent.

CONCLUSION

Ninety-four percent of patients with clinical symptoms of scurvy had vitamin C deficiency. Our results suggest that in hospitalized elderly patients, clinical symptoms allow scurvy diagnosis. Scurvy could be a frequent disease in elderly patients admitted to acute geriatric ward.

Vitamin C deficiency increases basal exploratory activity but decreases scopolamine-induced activity in APP/PSEN1 transgenic mice

Vitamin C is a powerful antioxidant and its levels are decreased in Alzheimer's patients. Even sub-clinical vitamin C deficiency could impact disease development. To investigate this principle we crossed APP/PSEN1 transgenic mice with Gulo knockout mice unable to synthesize their own vitamin C. Experimental mice were maintained from 6 weeks of age on standard (0.33 g/L) or reduced (0.099 g/L) levels of vitamin C and then assessed for changes in behavior and neuropathology. APP/PSEN1 mice showed impaired spatial learning in the Barnes maze and water maze that was not further impacted by vitamin C level. However, long-term decreased vitamin C levels led to hyperactivity in transgenic mice, with altered locomotor habituation and increased omission errors in the Barnes maze. Decreased vitamin C also led to increased oxidative stress. Transgenic mice were more susceptible to the activity-enhancing effects of scopolamine and low vitamin C attenuated these effects in both genotypes. These data indicate an interaction between the cholinergic system and vitamin C that could be important given the cholinergic degeneration associated with Alzheimer's disease.

Scurvy: forgotten but definitely not gone

Scurvy, a disease of vitamin C deficiency, is purportedly rare in the United States yet frequently may be misdiagnosed. Presenting symptoms include bone pain, limping, rashes, or spongy bleeding gingiva. These symptoms mimic many other disorders, which often results in numerous unnecessary, invasive, and expensive procedural investigations. The strongest indication of a scurvy diagnosis is the dramatic response to the administration of vitamin C. This case report demonstrates the complexities involved in determining the cause of one child's symptoms. A thorough nutritional history and a shrewd clinician are essential to the early diagnosis and treatment of scurvy.

Vitamin C deficiency in early postnatal life impairs spatial memory and reduces the number of hippocampal neurons in guinea pigs

BACKGROUND

The neonatal brain is particularly vulnerable to imbalances in redox homeostasis because of rapid growth and immature antioxidant systems. Vitamin C has been shown to have a key function in the brain, and during states of deficiency it is able to retain higher concentrations of vitamin C than other organs. However, because neurons maintain one of the highest intracellular concentrations of vitamin C in the organism, the brain may still be more sensitive to deficiency despite these preventive measures.

OBJECTIVE

The objective was to study the potential link between chronic vitamin C deficiency and neuronal damage in newborn guinea pigs.

DESIGN

Thirty 6- to 7-d-old guinea pigs were randomly assigned to 2 groups to receive either a vitamin C-sufficient diet or the same diet containing a low concentration of vitamin C (but adequate to prevent scurvy) for 2 mo. Spatial memory was assessed by the Morris Water Maze, and hippocampal neuron numbers were quantified by stereologic techniques.

RESULTS

The results showed a reduction in spatial memory (P < 0.05) and an increased time to first platform hit (P < 0.05) in deficient animals compared with controls. The deficient animals had a lower total number of neurons in hippocampal subdivisions (dentate gyrus, cornu ammonis 1, and cornu ammonis 2-3) than did the normal controls (P < 0.05).

CONCLUSIONS

Our data show that vitamin C deficiency in early postnatal life results in impaired neuronal development and a functional decrease in spatial memory in guinea pigs. We speculate that this unrecognized effect of vitamin C deficiency may have clinical implications for high-risk individuals, such as in children born from vitamin C-deficient mothers.

Vitamin C deficiency in a university teaching hospital

OBJECTIVES

There is almost no information regarding the vitamin C status of patients treated in Canadian and American hospitals. We determined the prevalence and predictors of vitamin C deficiency in patients hospitalized on the acute-care wards of a Canadian teaching hospital, and tracked their plasma vitamin C concentrations while they were there.

METHODS

This was a population-based cross-sectional and time course survey of 149 medical patients shortly after admission to a university teaching hospital. The procedure for sample handling, storage and analysis was validated by measuring the vitamin C concentrations of a reference sample of 141 presumably well nourished people and comparing the results with published norms.

RESULTS

In keeping with published norms, 13% of people in the reference group had a subnormal vitamin C concentration (<28.4 micromol/L) and 3% were vitamin C deficient (<11.4 micromol/L). By contrast, 60% of hospitalized patients had a subnormal vitamin C concentration and 19% were deficient. A history of inadequate nutrition or failure to use a vitamin supplement prior to admission, low serum albumin, and male sex predicted plasma vitamin C deficiency, whereas use of a vitamin supplement prior to admission was associated with adequate vitamin C status in hospital. In a second measurement, obtained in 52 patients after an average of 17 days in hospital, vitamin C status had not improved.

CONCLUSIONS

Vitamin C deficiency is prevalent and sustained in patients in a Canadian teaching hospital. The abnormality can be prevented by providing a diet sufficient in vitamin C or by prescribing a multiple vitamin tablet.

Ascorbic acid deficiency in bariatric surgical population

BACKGROUND

To determine the prevalence of ascorbic acid deficiency in the surgical population, whether the body mass index (BMI) has an effect on ascorbic acid concentrations; and whether an association exists between ascorbic acid deficiency and adverse surgical outcomes.

METHODS

Preoperative plasma ascorbic acid concentrations were prospectively assessed in 20-60-year-old patients undergoing elective abdominal surgery. Ascorbic acid deficiency was defined as any concentration < or =0.3 mg/dL and depletion as any concentration >0.3-0.59 mg/dL.

RESULTS

Of the 266 patients evaluated, 167 had a BMI > or =35 kg/m(2). A greater BMI was associated with lower mean ascorbic acid concentrations (P = .021). Of the 266 patients, 96 (36%) had abnormally low ascorbic acid concentrations, with 57 (21%) depleted and 39 (15%) deficient. The factors associated with decreased mean ascorbic acid concentrations included younger age (P = .004) and limited vegetable and fruit intake (P = .026). Ascorbic acid supplementation was associated with lower depletion and deficiency rates (P = .001).

CONCLUSION

Ascorbic acid depletion and deficiency occur within the surgical population. The contributing factors included younger age, limited intake of fruits and vegetables, lack of vitamin supplementation, and greater BMI. Low concentrations of ascorbic acid did not affect the surgical outcome.

Plasma concentrations of ascorbic acid in parturients from a hospital in Southeast Brazil

BACKGROUND & AIMS

Pregnancy is a period characterized by high metabolic requirements and physiological changes in the female organism. During this period, low body stores of vitamins and minerals including antioxidants can have adverse effects on the mother and foetus. This cross-sectional study assessed plasma concentrations of ascorbic acid (AA) in 117 parturients admitted into a university hospital in São Paulo city, Brazil.

METHODS

The concentrations of AA were determined by the high performance liquid chromatographic method. Data concerning socioeconomic, demographic, obstetric and nutritional characteristics of the parturients were collected by a standardized questionnaire.

RESULTS

The prevalence of AA deficiency (<22.7 micromol/L) among the parturients was 30.8%. Mean plasma AA concentrations were lower in single/divorced women (27.84+/-3.48 micromol/L) compared with married/single with partner women (34.78+/-1.85 micromol/L) (p=0.047). Blood AA concentrations were significantly correlated with per capita income (r=0.36, p<0.001) and vitamin C-rich food intake score (r=0.42, p<0.001).

CONCLUSION

The high prevalence of hypovitaminosis C detected in this study is probably due to an inadequate intake of foods rich in vitamin C and low income. We alert to the need for increasing the intake of vitamin C-rich foods through educational programs, especially for low income populations.

Scurvy in a 10-month-old boy

We report a 10-month-old boy with inflammatory and necrotic gingival lesions, fever, irritability, and pseudoparalysis of the legs. Laboratory examinations revealed moderate anemia and skeletal X-rays showed osteopenia, scorbutic rosary at the costochondral junctions, and "corner sign" on the proximal metaphyses of the femora. The boy had been fed only with diluted cow's milk. He had never taken solid food, vitamin C, or iron complement. Seventy-two hours after starting oral vitamin C supplementation, there was significant improvement in the patient's gingival lesions and general health. The clinical presentation and laboratory and imaging findings, together with the dramatic response to ascorbic acid intake, allowed us to confirm the diagnosis of infantile scurvy. Scurvy, a dietary disease due to the deficient intake of vitamin C, is uncommon in the pediatric population. In an infant who has never received vitamin C, the combination of gingival lesions, pseudoparalysis, and irritability strongly suggests a diagnosis of scurvy. The clinical picture, together with the laboratory data, radiological studies, and therapeutic response to vitamin C administration, confirmed the diagnosis.

Marginal vitamin C status is associated with reduced fat oxidation during submaximal exercise in young adults

BACKGROUND

Vitamin C is a cofactor in the biosynthesis of carnitine, a molecule required for the oxidation of fatty acids. A reduction in the ability to oxidize fat may contribute to the reported inverse relationship between vitamin C status and adiposity. To examine this possibility, we conducted a preliminary trial to evaluate the impact of vitamin C status on fat oxidation during submaximal exercise.

METHODS

Fat energy expenditure was determined in individuals with marginal (n = 15) or adequate (n = 7) vitamin C status during a submaximal, 60-minute treadmill test. Subsequently, eight of the subjects with marginal vitamin C status completed an 8-week double-blind, placebo-controlled, depletion-repletion trial with submaximal exercise testing.

RESULTS

Individuals with marginal vitamin C status oxidized 25% less fat per kg body weight during the treadmill test as compared to individuals with adequate vitamin C status. Fat oxidation during exercise was inversely related to fatigue (r = -0.611, p = 0.009). Vitamin C repletion of vitamin C depleted subjects (500 mg vitamin C/d) raised fat energy expenditure during exercise 4-fold as compared to depleted control subjects (p = 0.011).

CONCLUSION

These preliminary results show that low vitamin C status is associated with reduced fat oxidation during submaximal exercise. Low vitamin C status may partially explain the inverse relationship between vitamin C status and adiposity and why some individuals are unsuccessful in their weight loss attempts.

Musculoskeletal manifestations of scurvy

Scurvy occurs in individuals who eat inadequate amounts of fresh fruit or vegetables, often because of dietary imbalances related to advanced age or homelessness. Asthenia, vascular purpura, bleeding, and gum abnormalities are the main symptoms. In 80% of cases, the manifestations of scurvy include musculoskeletal symptoms consisting of arthralgia, myalgia, hemarthrosis, and muscular hematomas. Vitamin C depletion is responsible for structural collagen alterations, defective osteoid matrix formation, and increased bone resorption. Imaging studies may show osteolysis, joint space loss, osteonecrosis, osteopenia, and/or periosteal proliferation. Trabecular and cortical osteoporosis is common. Children experience severe lower limb pain related to subperiosteal bleeding. Laboratory tests show nonspecific abnormalities including anemia and low levels of cholesterol and albumin. The finding of a serum ascorbic acid level lower than 2.5 mg/l confirms the diagnosis. Vitamin C supplementation ensures prompt resolution of the symptoms.

Grapefruit consumption improves vitamin C status in periodontitis patients

OBJECTIVE

Previous studies demonstrate a relationship between a lack of vitamin C and increased risk of periodontal disease. In the present study we examine the vitamin C plasma levels and inflammatory measures in periodontitis patients before and after the consumption of grapefruit.

SUBJECTS AND METHODS

Fifty-eight patients with chronic periodontitis were assigned to the test group (non-smokers n=21, smokers n=17) and a diseased control group (non-smokers n=11, smokers n=9). Furthermore, 22 healthy subjects were recruited to compare vitamin C plasma levels between periodontally diseased and healthy subjects. Clinical evaluations, including plaque index (PI), sulcus bleeding index (SBI), probing pocket depths (PPD) and plasma vitamin C levels, were performed at baseline, and after two weeks of grapefruit consumption.

RESULTS

At baseline, we observed significantly reduced plasma vitamin C levels in the test group and diseased controls in comparison with the healthy controls. On principle, smokers showed lower levels of vitamin C (mean 0.39 +/- 0.17 mg dl(-1)) than non-smokers (mean 0.56+/-0.29 mg dl(-1)). After grapefruit consumption, the mean plasma vitamin C levels rose significantly in the test group compared to the diseased controls (non-smokers: 0.87+/-0.39 mg dl(-1), smokers: 0.74+/-0.30 mg dl(-1)). Furthermore the SBI was reduced in the test group (non-smokers: from 1.68+/-0.6 to 1.05+/-0.6, p<0.001), whereas PI and PPD were unaffected.

CONCLUSION

The present results show that periodontitis patients are characterised by plasma vitamin C levels below the normal range, especially in smokers. The intake of grapefruit leads to an increase in plasma vitamin C levels and improves sulcus bleeding scores. Longer term studies are necessary to determine whether other periodontal outcomes improve with such supplementation especially in smokers.

Measurement of intracellular vitamin C levels in human lymphocytes by reverse phase high performance liquid chromatography (HPLC)

OBJECTIVES

Vitamin C plays an active role in many important metabolic processes, such as collagen formation and the prevention of bleeding. Although overt scurvy is now rare, there is evidence that subclinical vitamin C deficiency is still quite common. Serum and plasma vitamin C measurements do not correlate well with tissue levels while lymphocyte vitamin C levels provide the most accurate assessment of the true status of vitamin C stores and are not affected acutely by circadian rhythm or dietary changes. We report a specific and reproducible reverse phase high performance liquid chromatographic method (HPLC) for the quantification of vitamin C in lymphocytes.

METHODS

Reverse phase HPLC with a UV detection system was used. National Committee for Clinical Laboratory Standards (NCCLS) guidelines were followed for evaluation. Sample stability testing for lymphocyte vitamin C was performed for a period of 24 h at room temperature and 4 degrees C. Lymphocyte vitamin C levels were measured in 51 children.

RESULTS

Lymphocyte vitamin C measurement with HPLC revealed very good analytical sensitivity with a 1.42 microg/10(8) lymphocyte lower limit of detection on repeated testing. An external standard curve was used for quantification, which showed a linear range of 1.25-100 microg/10(8) lymphocyte with a correlation coefficient of 0.989. Precision studies showed an inter-assay repeatability coefficient of variance (CV) between 0.25-9.98% and a within-assay coefficient of variance between 1.2-12.49%. The inter-assay CV for a period of 20 days was less than 10% for concentrations equal to or less than 1.42 microg/10(8) lymphocytes and less than 5.5% for concentrations between 5-100 microg/10(8) lymphocytes. Vitamin C was most stable at 4 degrees C, with a 0.31% decrease after 3 h and 2.35% after 4 h. At room temperature, vitamin C loss was more significant, with losses of 8.44% and 15.6% at 3 and 4 h, respectively, at a concentration of 29.9 microg/10(8) lymphocytes.

CONCLUSIONS

The proposed HPLC method offers a reliable and reproducible technique for the quantification of intracellular vitamin C. Lymphocyte samples can be rapidly prepared and represent a more homogeneous tissue sample source for intracellular vitamin C measurement as compared to serum. To ensure stability, lymphocyte lysates should be prepared and stored at or below -20 degrees C within 2 h of blood collection.

Pilot Study of a Moderate Dose Multivitamin/Mineral Supplement for Children with Autistic Spectrum Disorder

OBJECTIVE

Determine the effect of a moderate dose multivitamin/mineral supplement on children with autistic spectrum disorder.

DESIGN

Randomized, double-blind, placebo-controlled 3-month study.

SUBJECTS

Twenty (20) children with autistic spectrum disorder, ages 3-8 years.

RESULTS

A Global Impressions parental questionnaire found that the supplement group reported statistically significant improvements in sleep and gastrointestinal problems compared to the placebo group. An evaluation of vitamin B(6) levels prior to the study found that the autistic children had substantially elevated levels of B6 compared to a control group of typical children (75% higher, p < 0.0000001). Vitamin C levels were measured at the end of the study, and the placebo group had levels that were significantly below average for typical children, whereas the supplement group had near-average levels.

DISCUSSION

The finding of high vitamin B(6) levels is consistent with recent reports of low levels of pyridoxal-5-phosphate and low activity of pyridoxal kinase (i.e., pyridoxal is only poorly converted to pyridoxal-5-phosphate, the enzymatically active form). This may explain the functional need for high-dose vitamin B(6) supplementation in many children and adults with autism.

Carences en vitamine C

BACKGROUND

Hypovitaminosis C is frequent in populations at risk (men who live alone, old people, homelessness, patients with psychiatric diseases, foodfaddists,...) and is underestimated in the general population.

STRONG POINTS

Scurvy occurs after 3 months without consumption of ascorbic acid, and is due to lack of consumption fresh fruits and vegetables. Clinical manifestations are weakness, myalgia and arthralgia, vascular purpura and hemorrhagic syndrome, and later the stomatologic manifestations: gingivorragia and loss of teeth. Biological signs are nonspecific: anemia, hypocholesterolemia, hypoalbuminemia. Clinical suspicion must be confirmed by a low level of ascorbic acid (<2.5 mg/l), but this value needs to be interpretated according to the presence of an acute phase response. Leucocyte ascorbic acid level reflects total body store and is more reliable, but not available in practice. Treatment consists in administration of 1 g vitamin C per day during 15 days.

PERSPECTIVES

Vitamin C depletion (serum ascorbic acid level between 2 and 5 mg/l) may occur long-term complications such as increase cardiovascular and neoplasic risks or cataract. The new recommended dietary allowance of vitamin C (110 mg per day for an adult) takes into account of these risks.

Vitamin C deficiency and depletion in the United States: the Third National Health and Nutrition Examination Survey, 1988 to 1994

OBJECTIVES

We sought to determine prevalence rates of vitamin C deficiency and depletion in the United States.

METHODS

We used data from the Third National Health and Nutrition Examination Survey to assess intake of dietary, supplemental, and serum vitamin C.

RESULTS

Mean intakes and serum levels of vitamin C were normal; however, vitamin C deficiency and depletion were common (occurring among 5%-17% and 13%-23% of respondents, respectively). Smokers, those who did not use supplements, and non-Hispanic Black males had elevated risks of vitamin C deficiency, while Mexican Americans had lower risks.

CONCLUSIONS

Health professionals should recommend consumption of vegetables and fruits rich in vitamin C and should recommend supplementation for individuals at risk of vitamin C deficiency.

Hypovitaminosis C in hospitalized patients

BACKGROUND: In recent years, cases of scurvy have mainly been described in populations at risk. The prevalence and risk factors for hypovitaminosis C among hospitalized patients in a department of internal medicine are largely unknown. METHODS: We determined serum ascorbic acid level (SAAL) and searched for clinical and biological signs of scurvy in 184 patients hospitalized during a 2-month period. RESULTS: The prevalence of hypovitaminosis C (depletion: SAAL<5 mg/l or deficiency: SAAL<2 mg/l ) was 47.3%. Some 16.9% of the patients had vitamin C deficiency. There was a strong association between hypovitaminosis C and the presence of an acute phase response (p=0.002). Other univariate risk factors for vitamin C depletion were male sex (p=0.02), being retired (p=0.037), and infectious diseases (p=0.002). For vitamin C deficiency, the significant univariate risk factors included the same ones found for vitamin C depletion, plus being unemployed (p=0.003) and concomitant excessive alcohol and tobacco consumption (p<0.0001). Logistic regression showed that being retired (p=0.015) and concomitant excessive alcohol and tobacco consumption (p=0.0003) were significant independent risk factors. Hemorrhagic syndrome and edema were described more often in patients with vitamin C deficiency than in those with vitamin C depletion or without hypovitaminosis. Clinical signs were more frequent for an ascorbic acid level below 2.5 mg/l. CONCLUSION: Hypovitaminosis C is frequent in hospitalized patients but should be interpreted according to the presence or absence of an acute phase response. The main risk factors are living conditions and excessive alcohol and tobacco consumption.