Vitamin C Deficiency in Critically Ill Children: Prospective Observational Cohort Study.

OBJECTIVES: To evaluate the presence of vitamin C deficiency in critically ill children admitted to the PICU. DESIGN: Single-center prospective observational cohort study. SETTING: A 28-bed PICU and a pediatric outpatient sedation room of a tertiary-care teaching hospital. PATIENTS: Two pediatric patient groups 0-21 years old were studied: a PICU group and a group receiving deep sedation for elective outpatient procedures (noncritical care group). INTERVENTIONS: Vitamin C level was drawn for the PICU group within 24 hours of admission. Vitamin C level was drawn prior to start of deep sedation for the noncritical group. MEASUREMENT AND MAIN RESULTS: Vitamin C deficiency was present in 11/60 (18%) in the PICU group and 0/21 (0%) of the noncritical group (p < 0.05). CONCLUSIONS: Vitamin C deficiency was prevalent in our patients admitted to PICU.

Vitamin C deficiency and impact of vitamin C administration among pediatric patients with advanced chronic kidney disease.

BACKGROUND: Vitamin C deficiency is common in chronic kidney disease (CKD) due to losses through dialysis and dietary intake below requirement. We investigated prevalence of vitamin C deficiency and impact of vitamin C treatment in deficient/insufficient patients. METHODS: A prospective cohort study in patients aged 1-18 years with CKD stages 4 and 5D collected demographic data including underlying disease, treatment, and anthropometric assessment. Vitamin C intake was assessed using 24-h dietary recall. Hemoglobin, iron status, serum vitamin C, and serum oxalate were measured at baseline and after treatment. Vitamin C (250 mg/day) was given orally for 3 months to deficient/insufficient patients. RESULTS: Nineteen patients (mean age 12.00 ± 4.1 years) showed prevalence of 10.6% vitamin C insufficiency and 78.9% deficiency. There were no associations between vitamin C level and daily vitamin C intake (p = 0.64) or nutritional status (p = 0.87). Median serum vitamin C was 1.51 (0.30-1.90) mg/L. In 16 patients receiving treatment, median serum vitamin C increased from 1.30 (0.23-1.78) to 3.22 (1.77-5.96) mg/L (p = 0.008) without increasing serum oxalate (79.92 (56.6-106.84) vs. 80.47 (56.88-102.95) µmol/L, p = 0.82). However, 62.5% failed to achieve normal vitamin C levels. Ordinal regression analysis revealed patients with non-oligoanuric CKD were less likely to achieve normal vitamin C levels (ß = - 3.41, p = 0.03). CONCLUSION: We describe high prevalence of vitamin C insufficiency/deficiency among pediatric CKD patients. Vitamin C levels could not be solely predicted by nutritional status or daily intake. The treatment regimen raised serum vitamin C without increasing serum oxalate; however, it was largely insufficient to normalize levels, particularly in non-oligoanuric CKD. Graphical abstract .

Adding an orange to the banana bag: vitamin C deficiency is common in alcohol use disorders.

BACKGROUND: At least a third of the world's population consumes alcohol regularly. Patients with alcohol use disorders (AUDs) are frequently hospitalized for both alcohol-related and unrelated medical conditions. It is well recognized that patients with an AUD are thiamine deficient with thiamine replacement therapy being considered the standard of care. However, the incidence of vitamin C deficiency in this patient population has been poorly defined. METHODS: In this retrospective, observational study, we recorded the admission vitamin C level in patients with an AUD admitted to our medical intensive care unit (MICU) over a 1-year period. In addition, we recorded relevant clinical and laboratory data including the day 2 and day 3 vitamin C level following empiric treatment with vitamin C. Septic patients were excluded from this study. RESULTS: Sixty-nine patients met the inclusion criteria for this study. The patients' mean age was 53 ± 14 years; 52 patients (75%) were males. Severe alcohol withdrawal syndrome was the commonest admitting diagnosis (46%). Eighteen patients (26%) had cirrhosis as the admitting diagnosis with 18 (13%) patients admitted due to alcohol/drug intoxication. Forty-six patients (67%) had evidence of acute alcoholic hepatitis. The mean admission vitamin C level was 17.0 ± 18.1 µmol/l (normal 40-60 µmol/l). Sixty-one (88%) patients had a level less than 40 µmol/l (subnormal) while 52 patients (75%) had hypovitaminosis C (level < 23 µmol/l). None of the variables recorded predicted the vitamin C level. Various vitamin C replacement dosing strategies were used. A 1.5-g loading dose, followed by 500-mg PO q 6, was effective in restoring blood levels to normal by day 2. CONCLUSION: Our results suggest that hypovitaminosis C is exceedingly common in patients with an AUD admitted to an intensive care unit and that all such patients should receive supplementation with vitamin C in addition to thiamine. Additional studies are required to confirm the findings of our observational study and to determine the optimal vitamin C dosing strategy.

Vitamin C deficiency in Australian hospitalised patients: an observational study.

BACKGROUND: Vitamin C has anti-oxidant properties and acts as a cofactor for several enzymes. Hypovitaminosis C has been associated with bleeding, endothelial dysfunction and death. The prevalence of hypovitaminosis C is unknown in Australian hospitalised patients, and its clinical relevance is uncertain. AIMS: To determine the prevalence, characteristics and clinical outcomes of hospitalised patients with hypovitaminosis C. METHODS: This observational study included general-medical inpatients in a tertiary-level hospital in Australia. High-performance liquid chromatography (HPLC) was used to determine plasma vitamin C levels. As per Johnston's criteria, vitamin C levels of ≥28 µmol/L were classified as normal and <28 µmol/L as low. Clinical outcomes determined included length of hospital stay (LOS), nosocomial complications, intensive care unit admission and in-hospital mortality. RESULTS: A total of 200 patients participated in this study, and vitamin C levels were available for 149 patients, of whom 35 (23.5%) had normal vitamin C levels, and 114 (76.5%) had hypovitaminosis C. Patients with hypovitaminosis C were older and had higher C-reactive protein (CRP) levels. Median LOS was 2 days longer in patients with hypovitaminosis C (6 days (interquartile range (IQR) 4, 8) vs 4 days (IQR 3, 6), P = 0.02), and they had fourfold higher odds of staying in hospital for >5 days than those with normal vitamin C levels. Other clinical outcomes were similar between the two groups. CONCLUSIONS: Hypovitaminosis C is common in hospitalised patients and is associated with prolonged LOS. Further research is needed to ascertain the benefits of vitamin C supplementation in vitamin C-depleted patients.

Appropriate vitamin D loading regimen for patients with advanced lung cancer.

BACKGROUND: Most patients attending cancer clinics have hypovitaminosis D. Correcting or preventing this abnormal condition could mitigate the emotional and physical complications of their disease, but clinical trials of vitamin D therapy in this setting are hindered by the unavailability of safe, effective and practical loading dose regimens. METHODS: In this single arm open-label pharmacokinetic trial, outpatients with advanced lung cancer consumed 20,000 IU vitamin D daily with the largest meal of the day for 14 days followed by 10,000 IU per day for a further 7 days. Plasma concentrations of 25-hydroxyvitamin D [25(OH)D], parathyroid hormone, calcium, vitamin C and C-reactive protein were measured on protocol days 0, 14 and 21, and serum vitamin D binding protein (VDBP) concentrations on days 0 and 21. As a secondary objective, preliminary information was obtained regarding clinical effects of rapid vitamin D loading on mood and symptoms by administering appropriate questionnaires two times at baseline and after 14 and 21 days of vitamin D therapy. RESULTS: Of the 91 patients enrolled in the study, 85 % had hypovitaminosis D and 41 % had hypovitaminosis C. Plasma VDBP concentrations were in the normal range. The vitamin D load increased the average plasma 25(OH)D concentration to 116 ± 34 nmol/L (mean ± SD); the median concentration was 122 nmol/L (interquartile range 103-134); VDBP concentrations did not change. Final plasma 25(OH)D concentrations were subnormal (<75 nmol/L) for 13 % of the patients and sub-target (<120 nmol/L) for 44 % of them. In most cases, subnormal and sub-target 25(OH)D concentrations were attributable to obesity and/or a low baseline 25(OH)D concentration. Mood and symptom scores did not change significantly throughout the 3-week protocol. CONCLUSION: Hypovitaminosis D and C are very common in outpatients with advanced lung cancer. A vitamin D load of 20,000 IU per day for 14 days failed to achieve the target concentration in 44 % of the participants in this trial. These results suggest that a loading dose of 30,000 IU per day for 14 days would be safe and effective for patients who are obese or at risk of severe hypovitaminosis D. The preliminary nature of the study design, and the failure to achieve target 25(OH)D concentrations for a large proportion of the patients, do not allow any firm conclusion about the clinical effects of correcting hypovitaminosis D in this patient population. Nevertheless, no evidence was obtained that partial correction of hypovitaminosis D greatly improved mood, reduced distress or relieved cancer-related symptoms. This trial was registered at clinicaltrials.gov as NCT01631526.

Vitamin C status of Canadian adults: Findings from the 2012/2013 Canadian Health Measures Survey.

BACKGROUND: Although vitamin C is not produced in the body, it is important for many biochemical and physiological functions. Little is known about the current vitamin C status of Canadians. This study describes the correlates of vitamin C status in a nationally representative sample of adults. DATA AND METHODS: Data are from the 2012/2013 Canadian Health Measures Survey. Plasma vitamin C (L-ascorbic acid) concentrations were measured among a fasting subsample of respondents aged 20 to 79 (n = 1,615). Vitamin C status, prevalence of deficiency (plasma vitamin C < 11 µmol/L), and use of vitamin C-containing supplements were estimated. Multivariate regression models were used to examine associations between vitamin C status and sociodemographic characteristics, smoking, body mass index, supplement use, and consumption of fruit juice and citrus fruit. RESULTS: The mean plasma vitamin C concentration of adults aged 20 to 79 was 53 µmol/L; fewer than 3% were vitamin C-deficient. Almost 22% took a vitamin C-containing supplement. Concentrations were lower among smokers and people who were obese, and higher among vitamin C supplement users and fruit juice and citrus fruit consumers. Multivariate models showed that supplement use was the strongest and most consistent predictor of vitamin C status; fruit juice and citrus fruit consumption were predictors only among populations with lower vitamin C concentrations (for example, smokers, obese). INTERPRETATION: Few Canadians were vitamin C-deficient. Smokers and people with a higher BMI were most at risk of lower vitamin C concentrations; concentrations were higher among supplement users and consumers of fruit juice and citrus fruit.

Micronutrient status and its effect on glycaemic indices in type 2 diabetics with foot ulcer in Ibadan, Nigeria.

BACKGROUND: Micronutrients are required by organisms in trace concentrations sufficient to maintain homeostasis. Deficiency of these elements could result in different medical and metabolic abnormalities. There are limited data on micronutrient status in type 2 diabetics with foot ulcer (DM+FU). Premised on this, this study investigated micronutrient levels of DM+FU and examined their effects on glycaemic indices. METHODS: One hundred and twenty participants, comprising seventy DM+FU and fifty non-diabetic participants (controls) aged 40-60 years, were recruited for the study. Ten millilitres of fasting blood samples were collected from each participant after obtaining their consent and levels of vitamin C, vitamin E, copper, selenium, zinc, FPG and HbAlc were measured. The data were analyzed using 't'- test and Pearson's correlation coefficients. Statistical significant was considered at p<0.05. RESULTS: FPG and HbAlc were significantly higher in DM+FU (12.98±0.43 mmol/l; 8.63±0.24 %) than in controls (5.09±0.08 mmol/l; 4.08±0.11 %). Vitamin C (3.7610.43 vs. 5.57±0.43 ptmol/l; p=0.003), vitamin E (19.57±1.01 vs. 25.57±0.27 pLimol/l; p=0.000) and selenium (0.48±0.01 vs. 0.81±0.04 srmol/l; p=0.000) were substantially lower in DM+FU compared with controls. However, no significant changes were observed when levels of copper and zinc were compared in all participants. Data revealed inverse associations between micronutrients and glycaemic indices (vitamin C/ FPG: (r= 0.250, p=0.037); Cu/HbA Ic: (r= 0.131, p=0.365)). CONCLUSIONS: Diabetics with foot ulcer were observed to be deficient in selenium, vitamin C and vitamin E. Therefore, type 2 diabetics with foot ulcer should be advised and encouraged to take more of leafy green vegetables and unsweetened fruits.

Deficiency of vitamin D and vitamin C in the pathogenesis of bronchial asthma.

Epidemiology of bronchial asthma (BA) indicates a marked paradox: rapid rise in the prevalence.Simultaneous decline in mortality is mostly related to improvement in the diagnosis and therapy. In many economically developed countries the BA affects more than 10 per cent of the population, while mortality related to this respiratory disorder is below 1/100,000. Factors favorably influencing mortality of BA include new more effective medications, decline in smoking and also improved nutrition, based on awareness of protective role of vitamins. Vitamin D deficiency has a number of biological effects that are potentially instrumental in the pathogenesis and severity of BA. Increased number of randomized, controlled, interventional studies is showing positive effects of vitamin D supplementation in pediatric and in adult BA. Oxidative stress is potentially an important pathogenic factor in the progression of BA. Vitamin C (ascorbic acid) belongs to the most effective nutritional antioxidants. By counteracting oxidants, reducing generation of reactive oxygen species, vitamin C may inhibit external attacks in the respiratory tract, thus modulating the development of BA (Fig. 2, Ref. 15).

The lower vitamin C plasma concentrations in elderly men compared with elderly women can partly be attributed to a volumetric dilution effect due to differences in fat-free mass.

Women show higher vitamin C plasma concentrations than men, but the reasons for this observation still require elucidation. The objective of the present study was to investigate whether sex differences in vitamin C plasma concentrations are present in elderly subjects and whether these differences are due to sex-specific lifestyles, total antioxidant status (TAOS) and/or body composition. Fasting plasma concentrations of vitamin C were assessed by photometric detection in a cross-sectional study of 181 women and eighty-nine men aged 62-92 years. Body composition was determined by bioelectrical impedance analysis. Vitamin C intake was assessed with a 3 d estimated dietary record. Stepwise multiple regression analyses were performed to investigate whether sex is an independent predictor of vitamin C plasma concentrations by controlling for age, vitamin C intake, lifestyle factors, TAOS and body composition. Women showed higher vitamin C plasma concentrations than men (76 v. 62 µmol/l, P< 0·0001). In the multiple regression analysis, male sex was a negative predictor of vitamin C plasma concentrations (ß = -0·214), as long as absolute fat-free mass (FFM) was not considered as a confounder. When absolute FFM was included, sex was no longer a predictor of vitamin C plasma concentrations, whereas absolute FFM (ß = -0·216), physical activity level (ß = 0·165), intake of vitamin C supplements (ß = 0·164), age (ß = 0·147) and smoking (ß = -0·125) affected vitamin C plasma concentrations. The results indicate that a higher absolute FFM, and thus a higher distribution volume of vitamin C, contributes to lower vitamin C plasma concentrations in men than women.

Java project on periodontal diseases: periodontal bone loss in relation to environmental and systemic conditions.

OBJECTIVE: To assess in a population deprived from regular dental care the relationship between alveolar bone loss (ABL) and environmental/systemic conditions. MATERIAL & METHODS: The study population consisted of subjects from the Purbasari tea estate on West Java, Indonesia. A full set of dental radiographs was obtained of each subject and amount of ABL was assessed. In addition, the following parameters were evaluated: plasma vitamin C, vitamin D3 , HbA1c and CRP, the haptoglobin phenotype, presence of putative periodontopathic bacteria and viruses, dietary habits, smoking and anthropometrics. RESULTS: In this population 45% showed vitamin C depletion/deficiency, 82% had vitamin D3 insufficiency/deficiency, 70% were in a pre-diabetic state, 6% had untreated diabetes, 21% had elevated CRP values ranging from 3.1 to 16.1 mg/l. Results of the regression analysis, including all above mentioned parameters, showed four significant predictors, explaining 19.8% of the variance of ABL. Number of Porphyromonas gingivalis cells and CRP values showed a positive relationship with ABL, whereas BMI and number of guava fruit servings were negatively related. CONCLUSION: Results confirm previous findings that elevated levels of P. gingivalis may be indicative for periodontitis progression. A new finding is that guava fruit consumption may play a protective role in periodontitis in a malnourished population.

Plasma ascorbic acid concentrations in prevalent patients with end-stage renal disease on hemodialysis.

OBJECTIVE: To determine the prevalence of vitamin C (ascorbic acid [AA]) deficiency in patients with end-stage renal disease, the effect of supplemental AA on plasma AA concentrations, and the extrinsic and intrinsic factors that affect plasma AA concentrations in this patient population. DESIGN: In study 1, we compared the effect of hemodialysis (HD) on plasma AA concentrations between patients with low and high pre-HD AA concentrations. In study 2, we analyzed kinetic and nonkinetic factors for their association with increased plasma AA concentrations in patients on maintenance HD. Study 1 was performed in a single outpatient HD clinic in Cherry Hill, New Jersey. Study 2 was performed in 4 outpatient HD clinics in Southern New Jersey. SUBJECTS AND INTERVENTION: In study 1, we collected plasma samples from 8 adult patients on maintenance HD at various time points around their HD treatment and assayed them for AA concentration. In study 2, we enrolled 203 adult patients and measured pre-HD plasma AA concentrations. We ascertained supplemental AA use and assessed dietary AA intake. MAIN OUTCOME MEASURE: In study 1, plasma AA concentrations were compared during the intradialytic and interdialytic period. In study 2, pre-HD plasma AA concentrations were correlated with supplement use and demographic factors. RESULTS: Study 1 showed that over the course of a single HD treatment, the plasma AA concentration decreased by a mean (±standard deviation) of 60% (±6.6). In study 2, the median pre-HD plasma AA concentration was 15.7 µM (interquartile range, 8.7-66.8) in patients who did not take a supplement and 50.6 µM (interquartile range, 25.1-88.8) in patients who did take a supplement (P < .001). Supplement use, increasing age, and diabetes mellitus were associated with a pre-HD plasma AA concentration ≥30 µM. CONCLUSION: HD depletes plasma AA concentrations, and AA supplementation allows patients to achieve higher plasma AA concentrations.

Vitamin C Deficiency of Korean Homeless Patients Visiting to Emergency Department with Acute Alcohol Intoxication.

Vitamins are essential micronutrients for maintenance of tissue functions. Vitamin deficiency is one of the most serious and common health problems among both chronic alcoholics and the homeless. However, the vitamin-level statuses of such people have been little studied. We evaluated the actual vitamin statuses of alcoholic homeless patients who visited an emergency department (ED). In this study the blood levels of vitamins B1, B12, B6, and C of 217 alcoholic homeless patients were evaluated retrospectively in a single urban teaching hospital ED. Vitamin C deficiency was observed in 84.3% of the patients. The vitamin B1, B12, and B6 deficiency rates, meanwhile, were 2.3%, 2.3%, and 23.5%, respectively. Comparing the admitted patients with those who were discharged, only the vitamin C level was lower. (P=0.003) In fact, the patients' vitamin C levels were markedly diminished, vitamin C replacement therapy for homeless patients should be considered in EDs.

Vegetable and fruit consumption, education and plasma vitamin C concentration in Russian and Finnish Karelia, 1992-2002.

OBJECTIVE: To examine (i) whether the consumption of fresh vegetables, fruit and berries is associated with plasma vitamin C concentration and (ii) educational differences in plasma vitamin C concentration in two neighbouring areas in Russia and Finland. DESIGN: Cross-sectional risk factor surveys in 1992, 1997 and 2002. Logistic regression analysis was applied to examine the associations of consumption of selected foods and education with plasma vitamin C concentration. SETTING: District of Pitkäranta in the Republic of Karelia, Russia and North Karelia, Finland. SUBJECTS: Adults aged 25-64 years: 579 men and 612 women in Pitkäranta; 974 men and 642 women in North Karelia. RESULTS: The plasma vitamin C concentration was strikingly low in Pitkäranta, Russia across the study years. During the 10 years of monitoring, the mean plasma vitamin C concentration among men ranged from 2·5 to 8·0 µmol/l in Pitkäranta, Russia and from 27·1 to 53·9 µmol/l in North Karelia, Finland. In both areas, daily consumption of fruit was most strongly associated with plasma vitamin C, while the association of fresh vegetable consumption with plasma vitamin C was less consistent. Consumption of berries was less important in explaining plasma vitamin C. In Pitkäranta, the plasma vitamin C concentration was lower among respondents in the lowest education group. CONCLUSIONS: Differences in the consumption of fresh vegetables and fruit resulted in notable differences in vitamin C status between Pitkäranta and North Karelia in spring. In comparative settings, knowledge of local food culture and validation pilots are important before conducting large population surveys.

Poor vitamin C status is associated with increased depression symptoms following acute illness in older people.

BACKGROUND: Vitamin C has important physical and mental health benefits and plasma concentrations reflect recent intakes. Inflammation associated with any acute illness can lead to poor appetite and low food intake in older people. The aims of this report were to assess the prevalence and clinical significance of vitamin C deficiency among hospitalized acutely-ill older patients. METHODS: Three hundred and twenty two patients (152 [47%] female), aged 65 yrs. and over who took part in a randomized, double blind, placebo-controlled trial had their nutritional status assessed from anthropometric, hematological and biochemical data at baseline, and after 6 weeks and 6 months. Vitamin C was measured using a fluorimetric technique and logistic regression analysis was performed to determine the influence of a number of clinical indicators, including tissue inflammation measured using C-reactive protein on vitamin C concentrations. Clinical outcome measures including symptoms of depression were also compared between patients with vitamin C deficiency and those with normal levels. RESULTS: At baseline, 116 (36%) patients had a vitamin C concentration below 11 µmol/L indicating biochemical depletion. The figures at 6 weeks and 6 months were 28 (22%) and 44 (28%) patients, respectively. Older age, male gender, smoking, increased dependency and tissue inflammation were associated with lower vitamin C concentrations. Patients with vitamin C biochemical depletion had significantly increased symptoms of depression compared with those with higher concentrations at baseline (p=0.035) and at 6 weeks (p=0.028). CONCLUSIONS: A high proportion of older patients had sub-optimal vitamin C status and this was associated with increased symptoms of depression.

Ascorbic acid deficiency amongst spondylodiscitis patients.

BACKGROUND: Spondylodiscitis can be a disabling and life-threatening infection. Ascorbic Acid is crucial for neutrophil function and collagen formation. Its association and clinical relevance in spondylodiscitis has not been previously examined. AIMS: To determine the prevalence, characteristics, and clinical outcomes of spondylodiscitis patients with Ascorbic Acid deficiency. METHODS: Sixty-eight consecutive patients admitted with spondylodiscitis, between December 2021 and August 2023 were included. Clinical characteristics, Ascorbic Acid levels and clinical outcomes were evaluated. RESULTS: Thirty-seven patients had Ascorbic Acid levels taken during admission. The median initial Ascorbic Acid level was 15 µmol/L with an IQR 6.5-27 µmol/L. Depletion defined as <28 µmol/L was present in 78% of patients. Deficiency defined as ≤11 µmol/L was present in and 46% of patients. Patients with depletion were more likely to require Intensive Care Admission (absolute risk increase = 24.1%; 2.6%-45.7%). Fifteen patients had repeat serum levels taken during admission with median increase of 17 µmol/L and an IQR 0-26 µmol/L. Patients that received supplementation had a significantly greater increase in Ascorbic Acid levels compared with those that did not receive supplementation (P = 0.002). CONCLUSION: Ascorbic acid deficiency is highly prevalent amongst spondylodiscitis patients. Depletion was associated with worse outcomes. Replacement significantly increased serum levels in comparison to standard hospital diet. The clinical significance of replacement remains to be evaluated.

Ozone exposure, vitamin C intake, and genetic susceptibility of asthmatic children in Mexico City: a cohort study.

BACKGROUND: We previously reported that asthmatic children with GSTM1 null genotype may be more susceptible to the acute effect of ozone on the small airways and might benefit from antioxidant supplementation. This study aims to assess the acute effect of ozone on lung function (FEF(25-75)) in asthmatic children according to dietary intake of vitamin C and the number of putative risk alleles in three antioxidant genes: GSTM1, GSTP1 (rs1695), and NQO1 (rs1800566). METHODS: 257 asthmatic children from two cohort studies conducted in Mexico City were included. Stratified linear mixed models with random intercepts and random slopes on ozone were used. Potential confounding by ethnicity was assessed. Analyses were conducted under single gene and genotype score approaches. RESULTS: The change in FEF(25-75) per interquartile range (60 ppb) of ozone in persistent asthmatic children with low vitamin C intake and GSTM1 null was -91.2 ml/s (p = 0.06). Persistent asthmatic children with 4 to 6 risk alleles and low vitamin C intake showed an average decrement in FEF(25-75) of 97.2 ml/s per 60 ppb of ozone (p = 0.03). In contrast in children with 1 to 3 risk alleles, acute effects of ozone on FEF25-75 did not differ by vitamin C intake. CONCLUSIONS: Our results provide further evidence that asthmatic children predicted to have compromised antioxidant defense by virtue of genetic susceptibility combined with deficient antioxidant intake may be at increased risk of adverse effects of ozone on pulmonary function.

[Vitamin C]. / Vitamine C.

Vitamin C is a water soluble vitamin which is mainly fresh fruits and vegetables foodborne. Vitamin C deficiency is most often due to a lack of daily amount. Scurvy is characterized by the occurrence of fatigue, myalgia, arthralgia, purpura, bleeding disorders, and later by dental manifestations. Biological signs are nonspecific: anemia, hypocholesterolemia, hypoalbuminemia. Clinical suspicion is confirmed by the decrease in ascorbic acid level (< 2 mg/L). It must be interpreted in light of the acute phase reactants. The treatment is the administration of 1 g of vitamin C per day for 15 days. Vitamin C depletion (ascorbic acid: 2 to 5 mg/L) could induce long-term complications. The recommended dietary allowance of vitamin C protect from these risks.

Joint effusions and purpura in multiply-transfused adult beta-thalassemia- clinical pointers to diagnosis of scurvy.

Periodic transfusions and effective chelation have ensured that thalassemics survive in to adulthood but their life is punctuated by peculiar problems in adulthood. Three cases of scurvy are being reported presenting uniquely as purpura, right hip joint effusion and right knee joint effusion with haemorrhage in prepatellar and retropatellar bursae, respectively over an 18 month period (2009-2010). The first two cases did give a history of gum bleed. None had any coagulation disturbance or transfusion-transmitted infections or connective tissue disorder. All the three cases responded dramatically to vitamin C supplementation. It is imperative to keep in mind that recurrent blood transfusions are associated with a state of subclinical vitamin C deficiency and overt scurvy may manifest as cumulative number of transfusions increase, as in adult thalassemics.

25 year experience of patterns of plasma vitamin C levels in patients requiring home parenteral support.

OBJECTIVE: Vitamin C deficiency is common in patients with chronic intestinal failure. Risk factors are poorly understood and guidelines for monitoring largely based on expert opinion. The aim of this study was to describe patterns of vitamin C deficiency in patients on long-term home parenteral support (HPS). DESIGN: A retrospective review of a prospectively collated database for 236 HPS patients cared for in Glasgow, from 1998 to 2023, was interrogated for subjects with paired CRP and vitamin C measurements. Following analysis of the impact of CRP on vitamin C levels, further review of associated clinical, micronutrient and dietetic details in those with a paired CRP <5 mg L-1 were used to identify risk factors for hypoascorbataemia. RESULTS: 1527 recorded episodes with paired CRP and vitamin C measurements were analysed. Period prevalence of hypoascorbataemia was between 29.3 and 52.5%, depending on choice of the lower reference range for vitamin C as either 15 µmol L-1 or 26.1 µmol L-1. The influence of CRP appeared most significant early during HPS with other factors, including extensive mucosal disease, precedent surgery or presence of a colostomy identified as more significant on multivariate analysis for those on long-term HPS (OR 1.3261-1.5609, 1.0752-1.1008, and 0.6260-0.6663 for threshold vitamin C of 26.1 or 15 µmol L-1 respectively). CONCLUSION: Vitamin C may present differently in long term HPS patients in comparison to those in the acute phase of illness. An evidence based approach to guideline development should be promoted to reduce morbidity.

Prevalence and prognostic significance of vitamin C deficiency in patients with acute upper gastrointestinal bleeding: a prospective cohort study.

BACKGROUND: Vitamin C is an essential dietary nutrient important for collagen synthesis, including within the gastrointestinal tract. AIM: We aimed to document the prevalence of Vitamin C deficiency (VCD) in patients who present with upper gastrointestinal bleeding (UGIB) and its association with clinical outcomes. METHODS: We conducted a prospective cohort study of patients presenting with UGIB. Fasting Vitamin C levels were collected at admission. Primary outcomes were the prevalence of VCD (Vitamin C level <23 µmol/L, severe VCD < 12 µmol/L) and a composite outcome of adverse events, stratified by VCD status. Secondary outcomes were prolonged hospitalisation and the need for ICU admission. RESULTS: A total of 227 patients were included (mean age 64.5 years, males 63.9%). VCD was identified in 74 (32.6%) and severe deficiency in 32 (14.1%) patients. VCD was associated with a higher composite endpoint of AE (45.9% vs 24.8%, p < 0.01), higher in-hospital mortality (9.5% vs 1.3%, p < 0.01), increased prolonged admissions (62.2% versus 47.1%, p = 0.03) and increased rebleeding (17.6% vs 7.8%, p = 0.03), compared with patients with normal Vitamin C levels. Multivariate logistic regression models showed that VCD was independently associated with the composite endpoint of AE. CONCLUSION: VCD is highly prevalent in patients with UGIB and associated with poorer outcomes, including higher mortality, rebleeding and length of stay. Interventional studies are required to determine the impact of early Vitamin C supplementation on clinical outcomes.