Electrocardiographic and blood pressure changes in apparently health male subjects following oral, chronic, low-dose vitamin c supplementation and /or change in posture

The aim of the present study was to investigate whether 2 weeks of vitamin C supplementation affects recovery from an unaccustomed bout of exercise. Sixteen male subjects were allocated to either a placebo (P; n = 8) or vitamin C group (VC; n = 8). The VC group consumed 200 mg of ascorbic acid twice a day, whereas the P group consumed identical capsules containing 200 mg of lactose. Subjects performed a prolonged (90-min) intermittent shuttle-running test 14 days after supplementation began. Post-exercise serum creatine kinase activities and myoglobin concentrations were unaffected by supplementation. However, vitamin C supplementation had modest beneficial effects on muscle soreness, muscle function, and plasma concentrations of malondialdehyde. Furthermore, although plasma interleukin-6 increased immediately after exercise in both groups, values in the VC group were lower than in the P group 2 hours after exercise (p < .05). These results suggest that prolonged vitamin C supplementation has some modest beneficial effects on recovery from unaccustomed exercise.

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Vitamin C Intake Reduces the Cytotoxicity Associated with Hyperglycemia in Prediabetes and Type 2 Diabetes

BioMed Research International ◽

10.1155/2013/896536 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Silvia Isabel Rech Franke ◽

Luiza Louzada Müller ◽

Maria Carolina Santos ◽

Arcênio Fishborn ◽

Liziane Hermes ◽

...

Keyword(s):

Type 2 Diabetes ◽

Dna Damage ◽

Vitamin C ◽

Low Dose ◽

Hemoglobin A1c ◽

Protein Glycation ◽

Glycation End Products ◽

Vitamin C Supplementation ◽

Type 2 Diabetic

Hyperglycemia leads to the formation of free radicals and advanced glycation end-products (AGEs). Antioxidants can reduce the level of protein glycation and DNA damage. In this study, we compared the levels of vitamin C intake, which is among the most abundant antioxidants obtained from diet, with the levels of fasting plasma glucose (FPG), glycated hemoglobin (A1C), DNA damage, and cytotoxicity in prediabetic subjects and type 2 diabetic subjects. Our results indicated that there was no significant correlation between FPG or A1C and DNA damage parameters (micronuclei, nucleoplasmic bridges, and nuclear buds). FPG and A1C correlated with necrosis (r=0.294;P=0.013andr=0.401;P=0.001, resp.). Vitamin C intake correlated negatively with necrosis and apoptosis (r=-0.246;P=0.040, andr=-0.276;P=0.021, resp.). The lack of a correlation between the FPG and A1C and DNA damage could be explained, at least in part, by the elimination of cells with DNA damage by either necrosis or apoptosis (cytotoxicity). Vitamin C appeared to improve cell survival by reducing cytotoxicity. Therefore, the present results indicate the need for clinical studies to evaluate the effect of low-dose vitamin C supplementation in type 2 diabetes.

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Effects of Vitamin C Supplementation on Glycemic Control and Cardiovascular Risk Factors in People With Type 2 Diabetes: A GRADE-Assessed Systematic Review and Meta-analysis of Randomized Controlled Trials

10.2337/figshare.13171967 ◽

2021 ◽

Author(s):

Shaun A Mason ◽

Michelle A Keske ◽

Glenn D Wadley

Keyword(s):

Risk Factors ◽

Blood Pressure ◽

Type 2 Diabetes ◽

Glycemic Control ◽

Vitamin C ◽

Controlled Trials ◽

Short Term ◽

Randomized Controlled ◽

Vitamin C Supplementation

<a>BACKGROUND </a>Evidence suggests vitamin C supplementation could be a potential therapy in type 2 diabetes. However, its effectiveness and evidence quality require further evaluation. PURPOSE To investigate the efficacy of oral vitamin C supplementation in improving glycemic control, cardiovascular risk factors, and oxidative stress in people with type 2 diabetes. DATA SOURCES Databases (PubMed, Embase, Scopus, Cochrane Library) and clinical trial registries were searched for randomized controlled trials up to 09/08/2020. STUDY SELECTION Trials in adults with type 2 diabetes were included. Trials were excluded if supplements were not exclusive to vitamin C, and if <2 weeks in duration. DATA EXTRACTION Primary outcomes were HbA1c, glucose, cholesterol, triglycerides, and blood pressure (BP). Data were extracted for changes in outcomes between vitamin C and control groups. Evidence certainty was assessed using GRADE methods. DATA SYNTHESIS Twenty-eight studies (n=1574) were included in the review. Outcomes changed to a statistically and clinically significant extent with Vitamin C were systolic BP (mean difference [MD] −6.27, 95% CI [−9.60, −2.96] mmHg; p=0.0002) with moderate evidence certainty; and HbA1c (MD −0.54 [−0.90, −0.17] %; p=0.004) and diastolic BP (MD −3.77 [−6.13, −1.42] mmHg; p=0.002) with very low evidence certainty. LIMITATIONS Studies were predominantly short-term (<6 months) with a small number of participants (n<100). <a>CONCLUSION While evidence from short-term studies suggests vitamin C supplementation may improve glycemic control and blood pressure in people with type 2 diabetes, vitamin C supplementation cannot currently be recommended as a therapy until larger, long-term and high quality trials confirm these findings. </a>

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Effects of vitamin C supplementation on blood pressure and hypertension control in response to ambient temperature changes in patients with essential hypertension

Clinical and Experimental Hypertension ◽

10.1080/10641963.2018.1501056 ◽

2018 ◽

Vol 41 (5) ◽

pp. 414-421 ◽

Cited By ~ 3

Author(s):

Xiaojie Yuan ◽

Xiaochun Li ◽

Zhaohua Ji ◽

Jing Xiao ◽

Lei Zhang ◽

...

Keyword(s):

Blood Pressure ◽

Essential Hypertension ◽

Vitamin C ◽

Ambient Temperature ◽

Hypertension Control ◽

Temperature Changes ◽

Vitamin C Supplementation

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Cardiovascular Benefits of Vitamin C Supplementation Against Particulate Air Pollution in Healthy Adults: A Double-Blind Randomized Crossover Trial

10.21203/rs.3.rs-1199803/v1 ◽

2022 ◽

Author(s):

Jingyi Ren ◽

Jufeng Liang ◽

Jiaqi Wang ◽

Bowen Yin ◽

Fan Zhang ◽

...

Keyword(s):

Blood Pressure ◽

Air Pollution ◽

Young Adults ◽

Vitamin C ◽

Crossover Trial ◽

Ambient Air ◽

Dietary Vitamin ◽

Double Blind ◽

Tnf Α ◽

Vitamin C Supplementation

Abstract Background: Accumulating evidence indicates that ambient air pollution exposure is associated with the adverse effects of cardiovascular diseases (CVDs). Evidence on the health benefits of vitamin C supplementation in highly polluted areas has not been evaluated. Objectives: We aims to evaluate whether dietary vitamin C supplementation can improve cardiovascular health linked to PM exposure. Methods: A randomized double-blind crossover trial was performed in 58 health young adults in Shijiazhuang, China in 2018. All subjects were randomly assigned to vitamin C supplementation or placebo group for a week alternating with a two-week washout period. We measured blood pressure (BP), blood lipid, biomarkers of oxidative and biomarkers of inflammation. Linear mixed-effect model was applied to evaluate the effect of vitamin C supplementation on health outcomes.Results: During the intervention periods, the average concentration of PM2.5 and PM10 was 164.91μg/m3 and 327.05μg/m3, respective. Vitamin C supplementation was significantly associated with decrease in several inflammatory indicators and blood pressure, including 19.47% in interleukin-6 (IL-6), 17.30% in tumor necrosis factor-a (TNF-α), 34.01% in C-reactive protein (CRP), 3.37% in systolic blood pressure (SBP) and 6.03% in pulse pressure (PP). Further, glutathione peroxidase (GSH-Px) was significantly increased by 7.15%. The effect of nutritional intervention on other indicators were beneficial, but there was no statistical difference. Gender-subgroup analysis showed that vitamin C supplementation significantly reduced SBP by 3.31%, PP by 4.94%, IL-6 by 20.97%, TNF-α by 27.85% and CRP by 38.5% in males, and significantly reduced SBP by 3.65%, PP by 8.12%, IL-6 by 17.35% and CRP by 29.15% in females. In contrast, vitamin C supplementation significantly increased APOB by 6.28% and GSH-Px by 14.47% in female participants only. Conclusion: This study indicates that vitamin C supplementation may protect cardiovascular system against particulate matter (PM) exposure among healthy young adults in China.Clinical trial registration information: Identifier: ChiCTR2100051371. Registered 19 October 2018, https://www.chictr.org.cn.

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Long-term vitamin C supplementation has no markedly favourable effect on serum lipids in middle-aged Japanese subjects

British Journal Of Nutrition ◽

10.1079/bjn20031024 ◽

2004 ◽

Vol 91 (1) ◽

pp. 81-90 ◽

Cited By ~ 15

Author(s):

Mi Kyung Kim ◽

Satoshi Sasaki ◽

Shizuka Sasazuki ◽

Shunji Okubo ◽

Masato Hayashi ◽

...

Keyword(s):

Vitamin C ◽

Dose Group ◽

Low Dose ◽

Favourable Effect ◽

High Dose ◽

Vitamin C Supplementation ◽

The Mean ◽

High Dose Vitamin ◽

Β Carotene

Antioxidant vitamins have been reported to be associated with an improvement in blood lipid profiles, but results are not consistent. The present study was designed to determine whether long-term vitamin C supplementation could alter serum lipid concentrations in subjects who completed a 5-year population-based double-blind intervention trial. A total of 439 Japanese subjects with atrophic gastritis initially participated in the trial using vitamin C and β-carotene to prevent gastric cancer. Before and upon early termination of β-carotene supplementation, 134 subjects dropped out of the trial; finally, 161 subjects assigned to the high-dose group (500 mg vitamin C/d) and 144 subjects assigned to the low-dose group (50 mg vitamin C/d) were studied. No favourable effect of vitamin C supplementation on serum concentrations of total cholesterol, HDL- and LDL-cholesterol, and triacylglycerol was observed, although high-dose vitamin C supplementation increased serum vitamin C concentrations substantially. Among women, the mean change in serum triacylglycerol decreased (−0·12 mmol/l, 95 % CI −0·32, 0·09) in the high-dose group, but increased (+0·12 mmol/l, 95 % CI 0·03, 0·22) in the low-dose group. In addition, the mean change in serum triacylglycerol among women with hypertriacylglycerolaemia was statistically significant (−1·21, 95 % CI −2·38, −0·05) after high-dose vitamin C supplementation. The 5-year vitamin C supplementation had no markedly favourable effects on the serum lipid and lipoprotein profile. However, our present results do not preclude the possibility that vitamin C supplementation may decrease triacylglycerol concentrations among women with hypertriacylglycerolaemia.

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