Vitamin C Intake Research Articles

The protective role of vitamin C on intestinal damage induced by high-dose glycinin in juvenile Rhynchocypris lagowskii Dybowski

This study was to evaluate the mitigative effects of vitamin C (VC) on growth inhibition and intestinal damage induced by glycinin in juvenile Rhynchocypris lagowskii Dybowski. 270 healthy juvenile Rhynchocypris lagowskii Dybowski (4.65 ± 0.04 g) were randomly divided into 3 treatments, and fed with control diet, 80 g/kg glycinin diet and 80 g/kg glycinin+200 mg/kg VC diet respectively for 8 weeks. The results showed that glycinin significantly decreased the weight gain rate, specific growth rate, protein efficiency rate, feed efficiency rate and feeding rate of fish compared with the control group (P < 0.05), while VC supplementation improved the growth performance and feed utilization efficiency, and reached a level similar to the control group. Similarly, VC significantly increased the crude protein content of muscle and whole-body, and hepatopancreas and intestinal protease activities of fish fed with glycinin diet (P < 0.05). The distal intestine of fish in glycinin group showed typical damage characteristics, including breakage and atrophy of intestinal mucosal fold, and increased intestinal mucosal permeability. However, fish fed the glycinin + VC diet showed an unimpaired normal intestinal morphology. Usefully, VC supplementation could also restore impaired immune function and antioxidant capacity. VC down-regulated the mRNA levels of pro-inflammatory cytokines TNF‐α and IL-1β, and up-regulated the mRNA levels of anti-inflammatory cytokines IL-10 and TGF-β in the distal intestine of fish fed with glycinin. Furthermore, glycinin exposure could reduce the mRNA levels of HO-1, CAT and GPx by inhibiting the activation of Nrf2-Keap1 signaling pathway, while VC supplementation reversed this phenomenon and maintained the homeostasis of antioxidant defense system. Concluded, glycinin causes growth inhibition, digestive dysfunction and intestinal damage of Rhynchocypris lagowskii Dybowski, while sufficient VC intake is beneficial for fish to resist the adverse effects of glycinin.

Decreasing Vitamin C Intake, Low Serum Vitamin C Level and Risk for US Adults with Diabetes.

Vitamin C (VC) intakes, serum VC, fasting plasma glucose, and A1c levels of 25,206 adult men and 26,944 adult women with 6807 type 2 and 428 type 1 diabetes from the NHANES database between 1999 and 2018 were analyzed. Our hypothesis is that low VC intake and serum VC level may be a health risk for US adults with diabetes. Analyses revealed total VC intake below the estimated average requirement (EAR) increased from 38.1% to 46.5% between 1999–2018. VC intake and serum VC levels were inversely associated with markers of pre-diabetes and type 2 diabetes, namely, fasting plasma glucose and A1c levels. Risks of type 2 diabetes increased in adults with VC intake below the EAR and with no VC supplement (odds ratio 1.20, 95% CI 1.1–1.3 and 1.28, 95% CI 1.18–1.40, respectively). Median survivor years of diabetic adults with lower and deficient serum VC were shorter than that of diabetic adults with normal serum VC. Mortality risks of type 2 diabetes with low VC intake and/or deficient serum VC levels were elevated compared to those with adequate VC intake and normal serum VC (HR 1.25, 95% CI 1.05–1.49 and 1.84, 95% CI 1.10–3.08, respectively). Observation of declining VC intake and deleterious consequences of low serum VC in US adults with diabetes suggests encouragement of VC intake, including VC supplementation of 500–1000 mg/day, may be beneficial for pre-diabetic and diabetic US adults.

A Causal Relationship between Vitamin C Intake with Hyperglycemia and Metabolic Syndrome Risk: A Two-Sample Mendelian Randomization Study.

Excessive oxidative stress can contribute to metabolic syndrome (MetS), and antioxidants can protect against its development. Vitamin C (VC) is a well-known antioxidant, and observational studies have associated a deficiency with an increased MetS risk. This study tested the hypothesis that dietary VC intake caused an inverse relation of MetS and its components risk using a two-sample Mendelian randomization (MR) method in adults ≥40 years in a city hospital-based (n = 58,701) and Ansan/Ansung plus rural (n = 13,598) cohorts. Independent genetic variants associated with dietary VC intake were explored using a genome-wide association study (GWAS) with significance levels of p < 5 × 10−5 and linkage disequilibrium (r2 threshold of 0.001), after adjusting for the covariates related to MetS, in a city hospital-based cohort (n = 52,676) excluding the participants having vitamin supplementation. MR methods, including inverse-variance weighting (IVW), weighted median, MR-Egger, and weighted model, were used to determine the causal relationship between the dietary VC intake and the risk of MetS and its components in Ansan/Ansung plus rural cohorts (n = 11,733). Heterogeneity and leave-one-out sensitivity analyses were conducted. Energy intake, as well as other nutrient intakes, were significantly lower in the low VC intake group than in the high VC intake group, but the incidence of MetS and its components, including hyperglycemia, hypertriglyceridemia, and hypertension, was observationally higher in inadequate low VC intake in the combined cohorts. In MR analysis, insufficient dietary VC intake increased the risk of MetS, hyperglycemia, hypertriglyceridemia, and hypertension in an IVW (p < 0.05). In contrast, only the serum fasting blood glucose concentration was significantly associated with VC intake in weight median analysis (p < 0.05), but there was no significant association of low dietary VC with MetS and its components in MR-Egger. There was no likelihood of heterogeneity and horizontal pleiotropy in MetS and its components. A single genetic variant did not affect their association in the leave-one-out sensitivity analysis. In conclusion, insufficient dietary VC intake potentially increased the MetS and hyperglycemia risk in Asian adults. Low VC intake can contribute to increasing type 2 diabetes incidence in Asians.

Vitamin C Intake and Cancers: An Umbrella Review.

Based on the existing systematic reviews and meta-analyses, we conducted this umbrella review aiming at evaluating the quality of evidence, validity and biases of the relationship between vitamin C (VC) intake and incidence and outcomes of multiple cancers. We identified 22 cancer outcomes within 3,562 articles. VC consumption was associated with lower incidence of bladder cancer, breast cancer, cervical tumors, endometrial cancer, esophageal cancer, gastric cancer, glioma, lung cancer, pancreatic cancer, prostate cancer, renal cell cancer, and total cancer occurrence. VC intake was also related to decreased risk of breast cancer prognosis (recurrence, cancer-specific mortality, and all-cause mortality).

Association between dietary antioxidant vitamins intake and homocysteine levels in middle-aged and older adults with hypertension: a cross-sectional study

ObjectivesPlasma total homocysteine (tHcy) has been implicated in the development of cardiovascular disease. This study aimed to assess the relationship of dietary antioxidant vitamins intake with tHcy levels in middle-aged...

Implementasi Konsep Health Belief Model terhadap Asupan Antioksidan Mahasiswa Gizi selama Pandemi COVID-19

Many recommendations were made by the Indonesia’s government to prevent the occurrence of COVID-19 infection. One of those recommendations is to make several behavioural changes, such asincreasing the consumption of foods containing vitamin A, C, E, and zinc to increase immunity system in the body. These eating pattern can be influenced by several factors, such as individual perceptions. Thepurpose of this study was to determine the relationship between the concept of the health belief model and the eating pattern of Nutrition Students of UNUSA during the COVID-19 pandemic. Method of this study was analytic observational study with cross sectional design. The instruments used in this study were online questionnaire regarding the health belief model and semi-quantitative food frequency questionnaire (SQFFQ). All respondents had a high perception of the seriousness of the COVID-19 disease, benefits in increasing consumption of healthy foods, support for eating healthy foods, and self efficacy to adopt healthy eating pattern. 47.8% of respondents had a low perception of barriers to healthy behavior, while 65.5% of respondents had a high perception of susceptibility to COVID-19 infection. Most of the respondents had adequate daily intake of vitamin A (93.8%) and vitamin C (74.3%). There was a difference in vitamin Cintake between the group with high perceived barrier and the low perceived barrier group (p value 0.037). There was significantly negative relationship between perceived barrier and vitamin E intake in the subjects, which means that if a person has higher barriers to consuming vitamin E, the person's vitamin E intake will also be lower. Keywords : COVID-19, health belief model, antioxidant, eating pattern

Altered Gut Microbiota is Involved in the Anti-Hypertensive Effects of Vitamin C in Spontaneously Hypertensive Rat.

Gut dysbiosis and dysregulation of the gut-brain-axis contributes to the pathogenesis of hypertension. Vitamin C (VC) is a common dietary supplement that shows the ability to lower the elevated blood pressure in hypertensive animals. Thus, the hypothesis that the gut microbiota is involved in the anti-hypertensive effect of VC is proposed. The changes of the gut microbiota and pathology in a spontaneously hypertensive rat (SHR) model after daily oral intake of VC in dosage of 200 or 1000mg kg-1 are examined. After 4 weeks, the elevated blood pressure of SHRs in both VC-treated groups is attenuated. Sequencing of the gut microbiota shows improvement in its diversity and abundance. Bioinformatic analysis suggests restored metabolism and biosynthesis-related functions of the gut, which are confirmed by the improvement of gut pathology and integrity. Analysis of the hypothalamus paraventricular nucleus (PVN), the central pivot of blood pressure regulation, also shows reduced inflammatory responses and oxidative stress. The reduced blood pressure, enriched gut microbiota, improved gut pathology and integrity, and reduced inflammatory responses and oxidative stress in the PVN together suggest that the anti-hypertensive effects of VC involve reshaping of gut microbiota composition and function.

Exercise and food supplement of vitamin C ameliorate hypertension through improvement of gut microflora in the spontaneously hypertensive rats

AimsExercise and food supplement of vitamin C (VC) are beneficial to human health, especially for those who suffer from hypertension. Here we tend to explore if gut microflora is involved in the anti-hypertensive effects of exercise and VC-supplement therapies. Materials and MethodsWith the spontaneously hypertensive rat (SHR) model, the small intestine pathology and the fecal microbiota was analyzed along with the pro- and anti-inflammatory cytokines (PICs and AICs) and reactive oxygen species (ROS) in the hypothalamus paraventricular nucleus (PVN) and intestine. Key findingsWe found that both exercise and VC intake, individually or combined, were able to alleviate the blood pressure in the SHRs comparing to the normotensive control Wistar-kyoto (WKY) rats. The expression level of PICs in the PVN and intestine of the SHRs was down-regulated while the AICs were up-regulated after treatments, together with down-regulation of ROS in the PVN. At meantime, the gut pathology was dramatically improved in the SHRs with exercise training or VC intake. Analysis of the gut microflora revealed significant changes in their composition. Several important micro-organisms that were deficient in the SHRs were found up-regulated by the treatments, including Turicibacter and Romboutsia which are involved in the short-chain fatty acid production. SignificanceExercise training and VC intake individually can modify the gut microflora composition and improve the inflammatory state in both PVN and intestine, which contribute to their anti-hypertensive function. Combination of the two treatments enhanced their effects and worth to be considered as a non-medical aid for the hypertensive patients.

Associations between dietary vitamin intake, ABCA1 gene promoter DNA methylation, and lipid profiles in a Japanese population

Higher intake of fruits and vegetables is associated with reduced risk of specific types of cancer and of cardiovascular disease (CVD), but the protective role of the vitamins contained in fruits and vegetables on CVD is controversial. This discrepancy can raise the question of the effects of antioxidants in vitamins on CVD. Recently, we reported that higher vegetable intake was significantly associated with the decreased DNA methylation level of ATP-binding cassette transporter A1 (ABCA1), a gene associated with HDL-cholesterol metabolism. We investigated whether ABCA1 DNA methylation mediates an effect of dietary vitamin intake on lipid profiles, an important risk factor for CVD, in a Japanese population. A total of 225 individuals (108 men and 117 women) with no clinical history and no drug use for dyslipidemia participated in this cross-sectional study. We used the pyrosequencing method to measure the ABCA1 DNA methylation levels at 8 CpG sites, and we used mean DNA methylation level in statistical analysis. Dietary vitamin intake was assessed with the FFQ and adjusted for the residual method. In women, higher dietary vitamin intake [vitamin A, β-carotene, folic acid, vitamin C (VC), vitamin D, and vitamin E] was significantly associated with lower mean ABCA1 DNA methylation levels (P=0.004, 0.03, 0.005, 0.001, 0.03, and 0.04, respectively). In addition, in women, we found a significant inverse association between mean ABCA1 DNA methylation and HDL cholesterol (P=0.04) but not for other lipid indexes. Mediation analysis showed a significant indirect effect of VC intake on HDL cholesterol through ABCA1 DNA methylation level in women (P=0.04). Although this study does not prove causality, the results suggest that ABCA1 DNA methylation mediates the protective effect of VC on HDL cholesterol in women, which could offer a novel biological mechanism in CVD prevention.

Behavioral and Neural Responses to Vitamin C Solution in Vitamin C-deficient Osteogenic Disorder Shionogi/Shi Jcl-od/od Rats.

To investigate the appetite for vitamin C (VC), we conducted behavioral and neural experiments using osteogenic disorder Shionogi/Shi Jcl-od/od (od/od) rats, which lack the ability to synthesize VC, and their wild-type controls osteogenic disorder Shionogi/Shi Jcl- +/+ (+/+) rats. In the behavioral study, rats were deprived of VC for 25 days and then received two-bottle preference tests with a choice between water and 10 mM VC. The preference for 10 mM VC solution of od/od rats was significantly greater than that of +/+ rats. In the neural study, the relative magnitudes of the whole chorda tympani nerve (CTN) responses to 100-1000 mM VC, 3-10 mM HCl, 100-1000 mM NaCl, and 20 mM quinine▪HCl in the VC-deficient rats were significantly smaller than those in the nondeficient ones. Further, we conducted additional behavioral experiments to investigate the appetite for sour and salty taste solutions of VC-deficient od/od rats. Preference scores for 3 mM citric acid increased in od/od rats after VC removal, compared with before, whereas preference scores for 100 and 150 mM NaCl were decreased in VC-deficient od/od rats. The preference for 300 mM NaCl was not changed. Hence, our results suggest that the reduction of the aversive taste of VC during VC deficiency may have involved the reduction of CTN responses to acids. Overall, our results indicate that VC-deficient rats ingest sufficient VC to relieve their deficiency and that VC deficiency causes changes in peripheral sensitivity to acids, but nongustatory factors may also affect VC intake and choice.

Membrane Permeabilities of Ascorbic Acid and Ascorbate.

Vitamin C (VC)—a collective term for the different oxidation and protonation forms of ascorbic acid (AscH)—is an essential micronutrient that serves as (i) a potent antioxidant and (ii) a cofactor of a manifold of enzymatic processes. Its role in health is related to redox balance maintenance, which is altered in diseases such as obesity, cancer, neurodegenerative diseases, hypertension, and autoimmune diseases. Despite its importance, VC uptake has been poorly investigated. Available literature values for the passive membrane permeability P of lipid bilayers for AscH scatter by about 10 orders of magnitude. Here, we show by voltage clamp that of AscH’s anionic form (ascorbate ) is negligible. To cross the membrane, picks up a proton in the membrane vicinity and releases it on the other side of the membrane. This leads to a near-membrane pH drop that was visualized by scanning pH microelectrodes. The AscH concentration dependent pH profiles indicated . Thus, AscH’s P is comparable to that of sorbitol and much lower than that of other weak acids like acetic acid or salicylic acid. The observation suggests that the capacity of the passive transcellular transport pathway across the lipid matrix does not suffice to ensure the required VC intake from the gastrointestinal tract.

Vitamin C supplementation improved the efficacy of foot-and-mouth disease vaccine

ABSTRACT Vitamin C (VC) is an essential micronutrient and plays important roles in various biological processes including immune responses. Vaccination can stimulate immune responses effectively for prevention of virual infection. Adequate VC intake is required for the immune system to function efficiently. In this study, we evaluated the biological function of VC on immune response to inactivated foot-and-mouth disease (FMD) vaccine. The C57BL/6 mice were injected intraperitoneally with different dose of VC daily following immunization with inactivated FMD vaccine. The results showed high dose of VC supplementation significantly increased IgG level. Similarly, high dose of VC supplementation enhanced Th2 and Th17 cellular immune responses and also increased MHCII expression on dendritic cells. Taken together, these data indicate that high dose of VC supplementation can modulate Th2 and Th17 cellular immune responses to inactivated FMD vaccine and manifest the necessity for effective vaccination.

ASSESSMENT OF DIFFERENCES IN VITAMIN C INTAKE BEFORE AND DURING RAMADAN AMONG GENERAL POPULATION IN KARACHI

BACKGROUND Inconsistent data revealed on investigation of nutrient intake by different populations of Muslims during Ramadan, particularly due to the variations in dietary norms. OBJECTIVES The purpose of this observational study was to find out the difference of Vitamin C intake before and during Ramadan within different age groups and genders. METHODS A prospective study was conducted to investigate Vitamin C intake of subjects on two occasions: before and during Ramadan. A total of 770 voluntary subjects (12–90 yrs.) were enrolled for the research. Informed consent form was obtained from each of the participant before the commencement of the study. A quantitative questionnaire cum interview method was used to collect demographic data, health characteristics and dietary intake data. Dietary data was collected using a 24 hour dietary recall and Generic Food Photograph Atlas (GFP) while food items were recorded in codes. Standardized Recipes were used to assess the amount of Vitamin C in each food consumed. Vitamin C intake was calculated with the help of the United States Department of Agriculture Food Composition Table (USDA FCT) and Allama Iqbal Open University Food Composition Table (AIOU FCT). Analysis was conducted using Paired-T-Test and MANOVA using Statistical Package for Social Sciences (SPSS) Software, Version 16. RESULTS A significant increase was observed in the overall intake of Vitamin C in the diet of participants during Ramadan (195.5% of before Ramadan intake). Moreover, the results indicated that Vitamin C consumption was increased among both males and females (P = &lt;0.05) and among heterogeneous aged subjects during Ramadan (P = &lt;0.05). CONCLUSION Additional research is warranted to further elucidate the increased intake of Vitamin C with regards of cultural differences. KEYWORDS Vitamin C, Before Ramadan, Intake, Generic Food Photograph Atlas, During Ramadan, Karachi

Effect of vitamins C and E on insulin resistance indiabetes: a meta-analysis study.

Data regarding the effect of vitamin C (VC) and vitamin E (VE) supplementation on insulin resistance in type 2 diabetes mellitus (T2DM) are controversial. We aimed to systematically review the current data on this topic. All randomized controlled trials (RCTs) conducted to assess the effect of VC and/or VE on insulin resistance in diabetes published in Google Scholar and PubMed web databases until January 2014 were included. Exclusion criteria were studies conducted in animal, type 1 DM, children or pregnant women. Main outcome measure was insulin resistance by homoeostasis model assessment (HOMA) index. According to degree of heterogeneity, fixed- or random-effect model was employed by stata software (11.0). We selected 14 RCTs involving 735 patients with T2DM. VE or mixture-mode supplementation did not have any significant effect on HOMA with a standardized mean difference (SMD): 0·017, 95% CI: -0·376 to 0·411 (P=0·932); and SMD: -0·035, 95% CI: -0·634 to 0·025 (P=0·070), respectively, by random-effect model. VC supplement alone did not improve insulin resistance with a SMD: -0·150, 95% CI: -0·494 to 0·194 (P=0·391), by fixed-effect model. Meta-regression test demonstrated that HOMA index may have not been influenced by the year of publication, dosage or duration of treatment. The sole intake of VC, VE or their combination with other antioxidants could not improve insulin resistance in diabetes.

High dietary intake of vitamin C suppresses age-related thymic atrophy and contributes to the maintenance of immune cells in vitamin C-deficient senescence marker protein-30 knockout mice.

Vitamin C (VC) is an essential nutrient for humans and certain other animals. It has antioxidant properties and has been reported to ameliorate oxidative damage to lipids, DNA and proteins. However, the effects of VC on immune function are poorly understood, especially the influence of long-term high-dose VC intake on the number and function of immune cells. In the present study, to evaluate the immune effects of VC, VC-deficient senescence marker protein-30 knockout (SMP30KO) mice were fed a diet containing the recommended level of VC (20 mg/kg per d; 0·02 % VC) or a high level of VC (200 mg/kg per d; 0·2 % VC) for 1 year. The plasma VC concentration of the 0·02 % group was the same as that of age-matched C57BL/6 mice after 1 year of feeding; however, plasma VC concentration and thymus weight were significantly higher in the 0·2 % VC group than in the 0·02 % VC group. The total counts of leucocytes, lymphocytes, granulocytes and monocytes in the peripheral blood, as well as the number of splenocytes and thymocytes, were all significantly higher in the 0·2 % VC group than in the 0·02 % VC group. In addition, the number of naive T cells in peripheral blood lymphocytes, the number of memory T-cell populations in splenocytes, and the number of cluster of differentiation (CD)4⁺CD8⁺ or CD4⁺CD8⁻ or CD4⁻CD8⁺ T cells in thymocytes were all markedly higher in the 0·2 % VC group than in the 0·02 % VC group after 1 year of dietary treatment. These results suggest that a long-term high-dose intake of VC is effective in the maintenance of immune cells, partly through the suppression of age-related thymic involution in VC-deficient SMP30KO mice.

Effect of dietary oxidized fish oil and vitamin C supplementation on growth performance and reduction of oxidative stress in Red Sea BreamPagrus major

A 50-day feeding trial was conducted to determine the effects of dietary oxidized fish oil (OFO) and vitamin C (VC) on growth and oxidative stress in juvenile red sea bream. Test diets were formulated with 2 degrees of peroxide value (23 and 29 meq kg−1) combined with 3 levels of VC (0, 400 and 800 ppm). No significant difference was found on growth performance between fish fed OFO with 400 or 800 mg VC and the control group that fed a diet with fresh fish oil after 50 days. However, fish fed OFO without VC supplement indicated significantly poor growth than the control group. Liver and muscle thiobarbituric acid reactive substances were reduced by increased VC intake of fish. Fish fed diets containing low OFO with 400 and 800 mg VC, high OFO with 800 mg VC, and fresh fish oil are allocated in the zone of high resistance against oxidative stress together with low oxidative stress condition. On the other hand, no VC supplemented group was under the highest oxidative stress condition. In conclusion, dietary oxidized lipid increased the oxidative stress condition of fish, but more than 400 mg VC kg−1 of dietary supplement improved growth and health of juvenile red sea bream.

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 (0.33 g/L), low (0.033 g/L) or zero (0 g/L) VC supplementation levels. After 4 weeks, 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.

Complete lack of vitamin C intake generates pulmonary emphysema in senescence marker protein-30 knockout mice

Vitamin C (VC) is a potent antioxidant and plays an essential role in collagen synthesis. As we previously reported, senescence marker protein-30 (SMP30) knockout (KO) mice cannot synthesize VC due to the genetic disruption of gluconolactonase (i.e., SMP30). Here, we utilized SMP30 KO mice deprived of VC and found that VC depletion caused pulmonary emphysema due to oxidative stress and a decrease of collagen synthesis by the third month of age. We grew SMP30 KO mice and wild-type (WT) mice on VC-free chow and either VC water [VC(+)] or plain water [VC(-)] after weaning at 4 wk of age. Morphometric findings and reactive oxygen species (ROS) in the lungs were evaluated at 3 mo of age. No VC was detected in the lungs of SMP30 KO VC(-) mice, but their ROS increased 50.9% over that of the VC(+) group. Moreover, their collagen content in the lungs markedly decreased, and their collagen I mRNA decreased 82.2% compared with that of the WT VC(-) group. In the SMP30 KO VC(-) mice, emphysema developed [21.6% increase of mean linear intercepts (MLI) and 42.7% increase of destructive index compared with VC(+) groups], and the levels of sirtuin 1 (Sirt1) decreased 16.8%. However, VC intake increased the MLI 16.2% and thiobarbituric acid reactive substances 22.2% in WT mice, suggesting that an excess of VC can generate oxidative stress and may be harmful during this period of lung development. These results suggest that VC plays an important role in lung development through affecting oxidant-antioxidant balance and collagen synthesis.

Augmentation of the acute phase response in vitamin C-supplemented ultramarathoners

Objective. To investigate the effects of vitamin C (VC) supplementation on the alterations in systemic markers of inflammation as a result of participation in a 90 km down run from Pietermaritzburg to Durban in 29 subjects who completed the 1999 Comrades Marathon. Interventions. Runners were divided into groups receiving 500 mg/day VC (VC500; N = 10), 1 500 mg/day VC (VC1500; N = 12) or placebo (P, N = 7) for 7 days before the race, on the day of the race, and for 2 days following completion. Main outcome measures. Each subject recorded dietary intake before, during and after the race and provided 35 ml blood samples 15 - 18 hours before the race, immediately post race, 24 hours post race and 48 hours post race. These were analysed for full blood count, vitamins A, C and E, glucose, C-reactive protein (CRP), amyloid A, interleukin-6 (IL-6) and interleukin-8 (IL-8) concentrations. All post race concentrations were adjusted for plasma volume changes. Results. Analyses of dietary intakes and blood glucose and anti-oxidant status on the day preceding the race and the day of the race excluded carbohydrate intake or plasma vitamins E and A as significant confounders in the study. Mean pre-race concentrations of serum vitamin C in VC500 and VC1500 groups (128 – 10.2 and 153 – 10.2 mol/l) were significantly higher (p &lt; 0.01) than in the P group (83 – 10.8 mol/l) and confirmed the additional dietary VC intake of both groups. Serum CRP concentrations were significantly higher (p &lt; 0.05) in the VC500 group than in the VC1500 and P groups. This finding was supported by similar trends in serum amyloid A, plasma IL-6 and IL-8. When the data from the two VC groups were pooled and the vitamin intake in the placebo (N = 7) and VC (N = 22) groups compared, CRP concentrations in the VC groups were significantly higher at each of the post-race time points (p &lt; 0.05). Conclusion. These data confirm previous findings of a trend towards an enhanced pro-inflammatory response following VC intake ≥500 mg per day. South African Sports Medicine Vol.17(1) 2005: 4-10

Augmentation of the acute phase response in vitamin C-supplemented ultramarathoners

Objective. To investigate the effects of vitamin C (VC) supplementation on the alterations in systemic markers of inflammation as a result of participation in a 90 km down run from Pietermaritzburg to Durban in 29 subjects who completed the 1999 Comrades Marathon. Interventions. Runners were divided into groups receiving 500 mg/day VC (VC500; N = 10), 1 500 mg/day VC (VC1500; N = 12) or placebo (P, N = 7) for 7 days before the race, on the day of the race, and for 2 days following completion. Main outcome measures. Each subject recorded dietary intake before, during and after the race and provided 35 ml blood samples 15 - 18 hours before the race, immediately post race, 24 hours post race and 48 hours post race. These were analysed for full blood count, vitamins A, C and E, glucose, C-reactive protein (CRP), amyloid A, interleukin-6 (IL-6) and interleukin-8 (IL-8) concentrations. All post race concentrations were adjusted for plasma volume changes. Results. Analyses of dietary intakes and blood glucose and anti-oxidant status on the day preceding the race and the day of the race excluded carbohydrate intake or plasma vitamins E and A as significant confounders in the study. Mean pre-race concentrations of serum vitamin C in VC500 and VC1500 groups (128 – 10.2 and 153 – 10.2 mol/l) were significantly higher (p &lt; 0.01) than in the P group (83 – 10.8 mol/l) and confirmed the additional dietary VC intake of both groups. Serum CRP concentrations were significantly higher (p &lt; 0.05) in the VC500 group than in the VC1500 and P groups. This finding was supported by similar trends in serum amyloid A, plasma IL-6 and IL-8. When the data from the two VC groups were pooled and the vitamin intake in the placebo (N = 7) and VC (N = 22) groups compared, CRP concentrations in the VC groups were significantly higher at each of the post-race time points (p &lt; 0.05). Conclusion. These data confirm previous findings of a trend towards an enhanced pro-inflammatory response following VC intake ≥500 mg per day. South African Sports Medicine Vol.17(1) 2005: 4-10