Vitamin C

[lower HS-CRP, HBP, FBG, HA1C, Insulin, HOMA-IR; extends mice, c elegans lifespan]

Effect of Vitamin C Supplementation on Insulin Resistance, β-cell Function and Insulin Sensitivity in Obese and Non Obese Individuals (January 2019)

Background: Insulin resistance (IR) is common pathological feature of most of the metabolic disorders including obesity. Vitamin C intake seems useful to counteract obesity and associated complications. 

Aim and Objectives: Present research was aimed to study the effect of vitamin C intake on fasting blood glucose, insulin, Homeostatic Model Assessment (HOMA) of Insulin Resistance (HOMA-IR), β-cell function (HOMA-β) and Quantitative Insulin Sensitivity Check Index (QUICKI) in obese and non obese subjects. 

Material and Method: Total 80 subjects; (42 centrally obese and 38 non obese) were involved in the present study, they received 500 mg vitamin C 3x a day for 3 months. Results: Significant decrease in fasting blood glucose, serum insulin, HOMA-IR and significant increase in QUICKI in all obese subjects and non obese males, except serum insulin in non obese males. No significant change in any of the parameters in non obese females and in HOMA-β, in all subjects was observed after vitamin C intake. 

Conclusion: This study indicates three months of 1500 mg/day of vitamin C intake is helpful to revert obesity and otherwise induced insulin resistance and increase insulin sensitivity index.

Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials, 2012

A meta-analysis of 29 small randomized controlled trials of short durations (median duration, 8 weeks) in 1,407 participants (10 to 120 subjects per trial; including both normotensive and hypertensive subjects) found that daily supplementation with 60 to 4,000 mg of vitamin C (median dose, 500 mg) reduced systolic blood pressure by 3.84 mm Hg and diastolic blood pressure by 1.48 mm Hg (45). Good quality long-term trials are needed to examine whether the anti-hypertensive effect of vitamin C is sustained over time and eventually results in a reduced risk of cardiovascular events.

Effects of Antioxidant Supplementation on Insulin Sensitivity, Endothelial Adhesion Molecules and Oxidative Stress in Normal Weight and Overweight Young Adults (2009)

Objective

To determine whether short-term antioxidant supplementation affects insulin sensitivity, endothelial adhesion molecule levels, and oxidative stress in overweight young adults.

Methods and Procedures

A randomized, double-blind, controlled study tested the effects of antioxidants (AOX) on measures of insulin sensitivity (homeostasis model assessment, HOMA and QUICKI), endothelial adhesion molecules (sICAM-1, sVCAM-1, sE-selectin), adiponectin and oxidative stress (lipid hydroperoxides, PEROX) in overweight and normal weight individuals (N=48, 18-30 years). Participants received either AOX (vitamin E 800IU, vitamin C 500mg, β-carotene 10mg) or placebo (PLC) for 8 weeks.

Results

HOMA values were initially higher in the overweight subjects and were lowered by week 8 (15% reduction, p=0.02). Adiponectin increased in both AOX groups. sICAM-1 and sE-selectin decreased in overweight AOX treated groups by 6% and 13%, respectively (p<0.05). Plasma PEROX were reduced by 0.31 and 0.70 nmol/ml in the normal weight and overweight AOX treated groups, respectively, by week 8 (p<0.05).

Discussion

AOX supplementation moderately lowers HOMA and endothelial adhesion molecule levels in overweight young adults. 

Vitamin C treatment reduces elevated C-reactive protein (2009)

Plasma C-reactive protein (CRP) is an inflammatory biomarker that predicts cardiovascular disease. Lowering elevated CRP with statins has reduced the incidence of cardiovascular disease. We investigated whether vitamin C or E could reduce CRP. Healthy nonsmokers (N=396) were randomized to three groups, 1000 mg/day vitamin C, 800 IU/day vitamin E, or placebo, for 2 months. Median baseline CRP was low, 0.85 mg/L. No treatment effect was seen when all participants were included. However, a significant interaction was found, indicating that treatment effect depends on baseline CRP concentration. Among participants with CRP indicative of elevated cardiovascular risk (> or =1.0 mg/L), vitamin C reduced the median CRP by 25.3% vs placebo (p=0.02) (median reduction in the vitamin C group, 0.25 mg/L, 16.7%). These effects are similar to those of statins. The vitamin E effect was not significant. In summary, treatment with vitamin C but not vitamin E significantly reduced CRP among individuals with CRP > or =1.0 mg/L. Among the obese, 75% had CRP > or =1.0 mg/L. Research is needed to determine whether reducing this inflammatory biomarker with vitamin C could reduce diseases associated with obesity. But research on clinical benefits of antioxidants should limit participants to persons with elevations in the target biomarkers.

Effect of vitamin C on inflammation and metabolic markers in hypertensive and/or diabetic obese adults: a randomized controlled trial

Subjects and methods

Sixty-four obese patients, who were hypertensive and/or diabetic and had high levels of inflammatory markers, from primary health care centers in Gaza City, Palestine, were enrolled into one of two groups in an open-label, parallel, randomized controlled trial. A total of 33 patients were randomized into a control group and 31 patients were randomized into an experimental group. The experimental group was treated with 500 mg vitamin C twice a day.

Results

In the experimental group, vitamin C significantly reduced the levels of high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), fasting blood glucose (FBG), and triglyceride (TG) after 8 weeks of treatment (overall: P<0.001); no changes appeared in total cholesterol (TC). In the control group, there were significant reductions in FBG and TG (P=0.001 and P=0.026, respectively), and no changes in hs-CRP, IL-6, or TC. On comparing the changes in the experimental group with those in the control group at the endpoint, vitamin C was found to have achieved clinical significance in treating effectiveness for reducing hs-CRP, IL-6, and FBG levels (P=0.01, P=0.001, and P<0.001, respectively), but no significant changes in TC or TG were found.

Conclusion

Vitamin C (500 mg twice daily) has potential effects in alleviating inflammatory status by reducing hs-CRP, IL-6, and FBG in hypertensive and/or diabetic obese patients.

Effect of vitamin C on blood glucose, serum lipids & serum insulin in type 2 diabetes patients (2007)

Background & objective: Diabetes mellitus is one of the most common metabolic disorders that causes micro- and macro-vascular complications. Because of additive effects of hyperglycaemia and hyperlipidaemia for cardiovascular diseases, lipid abnormalities should be evaluated in diabetes. As vitamin C is known for its beneficial effects on serum lipids and glycated haemoglobin (HbA1c), we evaluated the effect of different doses of vitamin C on blood glucose, serum lipids and serum insulin in individuals with type 2 diabetes mellitus.

Methods: A total of 84 patients with type 2 diabetes referred to Yazd Diabetes Research Center, Iran, were included in the study. They received randomly either 500 mg or 1000 mg daily of vitamin C for six weeks. Fasting blood sugar (FBS), triglyceride (TG), total cholesterol (TC), low and high density lipoprotein (LDL, HDL), glycated haemoglobin HbA(Ic) and serum insulin were measured before and after vitamin C consumption and the results were analyzed.

Results: A significant decrease in FBS, TG, LDL, HbA1c and serum insulin was seen in the group supplemented with 1000 mg vitamin C. The dose of 500 mg vitamin C, however, did not produce any significant change in any of the parameters studied.

Interpretation & conclusion: Our results indicate that daily consumption of 1000 mg supplementary vitamin C may be beneficial in decreasing blood glucose and lipids in patients with type 2 diabetes and thus reducing the risk of complications.

Ascorbic acid supplementation improves postprandial glycaemic control and blood pressure in individuals with type 2 diabetes: Findings of a randomized cross-over trial

Aim: The primary aim of this study was to investigate whether ascorbic acid (AA) supplementation improves postprandial glucose responses under free-living conditions in individuals with type 2 diabetes. A secondary aim was to investigate the effect of AA supplementation on blood pressure.

Materials and methods: A total of 31 individuals with type 2 diabetes (26 males and 5 females; aged 61.8 ± 6.8 years; duration of diabetes, 5.6 ± 4.6 years; HbA1c, 7.6% ± 0.7% [mean ± SD]) were enrolled in a randomized cross-over study involving 4 months of supplementation with oral AA (2 × 500 mg/d) or placebo. Participants wore continuous glucose monitors for 48 hours and consumed standardized meals pre- and post-supplementation. Measurements included postprandial glucose incremental areas under the curve (iAUC), duration of day in hyper- and hypo-glycaemia status, average 24-hour and daily postprandial glucose concentrations, HbA1c, insulin, blood pressure (BP) and oxidative stress (F2 -isoprostanes).

Results: Following AA supplementation, significant decreases were observed in daily postprandial glucose iAUC (-36%), in duration of day with hyperglycaemia (-2.8 h/d) and postprandial hyperglycaemia (-1.7 h/d), in average 24-hour glucose (-0.8 mmol/L) and daily postprandial glucose (-1.1 mmol/L) concentrations, in systolic (-7 mm Hg) and diastolic (-5 mm Hg) blood pressures and in a specific fraction of free plasma F2 -isoprostanes (-47 pg/mL) as compared to placebo.

Conclusions: Individuals with type 2 diabetes experienced improved postprandial and 24-hour glycaemia and decreased BP after 4 months of AA supplementation as compared to placebo. These findings offer evidence for the proposed use of AA as an adjunct therapy to improve glycaemic and BP control in individuals with type 2 diabetes.

Big Doses of Vitamin C May Lower Blood Pressure (link)

Miller and his colleagues reviewed and analyzed data from 29 randomized, controlled, previously published clinical trials that reported systolic and/or diastolic blood pressure values and also compared vitamin C intake to a placebo. What they found is that taking an average of 500 milligrams of vitamin C daily — about five times the recommended daily requirement — reduced blood pressure by 3.84 millimeters of mercury in the short term. Among those diagnosed with hypertension, the drop was nearly 5 millimeters of mercury.

By comparison, Miller says, patients who take blood pressure medication such as ACE inhibitors or diuretics (so-called “water pills”) can expect a roughly 10 millimeter of mercury reduction in blood pressure.

Vitamin C: Oral vs. Intravenous, Immune Effects, Cancer, Exercise Adaptation & More

https://www.youtube.com/watch?v=zfJQTyOklnE&t=2479s

Linus Pauling Institute (lots of cool info!)

https://lpi.oregonstate.edu/mic/vitamins/vitamin-C

Dr Thomas Levy: Vitamin C & The Great Supression

https://www.youtube.com/watch?v=z1kD3BolXnE

How to Make Vitamin C Serum (10% concentration by mass)

30mg Water + 15mg glycerin + 5mg ascorbic acid

Method1: https://www.youtube.com/watch?v=DVZQVA2Zmq0

Method2: https://www.youtube.com/watch?v=0JXu3_WHM08

4oz = 113g bottle => 10g vitc (2.5 tsp) + water => mix & use it in 2-3 weeks

Dietary vitamin C improves the survival of mice, 1984

Feeding C57BL/6J male mice 1% ascorbic acid (1,430 mg/kg body weight) in their drinking water for life increased the average life span by 8.6% (p less than 0.05) and perhaps by as much as 20.4%. The ascorbic acid group weighed 6-7% less than the control group up until 800 days of age. The maximum life span for the control group was 965 days and 993 days for the ascorbic acid group, representing an increase of only 2.9% in the maximum life span. The copper content of heart, liver, kidney, and brain was unchanged after feeding 1% ascorbic acid for 48 days. The copper content of heart declined by 20.4% after feeding 2% ascorbic acid. Liver, kidney, and brain were unchanged.

A method for oral administration of hydrophilic substances to Caenorhabditis elegans: Effects of oral supplementation with antioxidants on the nematode lifespan, 2009

Numerous studies using Caenorhabditis elegans have used a protocol in which chemicals are orally delivered by incorporating them into the nematode growth media or mixing them with the food bacteria. However, actual exposure levels are difficult to estimate as they are influenced by both the rates of ingestion into the intestine as well as absorption from the intestinal lumen. We used liposomes loaded with the hydrophilic fluorescent reagent uranin to test oral administration of water-soluble substances to C. elegans. Ingestion of liposomes loaded with fluorescent dye resulted in successful oral delivery of chemicals into the intestines of C. elegans. Using liposomes, oral administration of hydrophilic antioxidants (ascorbic acid, N-acetyl-cysteine, reduced glutathione, and thioproline) prolonged the lifespan of the nematodes, whereas the conventional method of delivery showed neither fluorescence nor longevity effects. Our method efficiently and quantitatively delivers solutes to nematodes.

Vitamin C intake and risk of renal cell carcinoma: a meta-analysis (link)

The overall Risk Reduction (95% CI) of RCC for the highest vs. the lowest levels of vitamin C intake was 0.78(0.69,0.87).  Little evidence of heterogeneity was found. 

The Long-Term Survival of a Patient With Stage IV Renal Cell Carcinoma Following an Integrative Treatment Approach Including the Intravenous α-Lipoic Acid/Low-Dose Naltrexone Protocol

After only a few treatments of IV α-lipoic acid and IV vitamin C, his symptoms began to improve, and the patient regained his baseline weight. His energy and outlook improved, and he returned to work. The patient had stable disease with disappearance of the signs and symptoms of stage IV RCC, a full 9 years following diagnosis, with a gentle integrative program, which is essentially free of side effects. As of November 2017 the patient feels well and is working at his full-time job.

Vitamin C may encourage blood cancer stem cells to die -- ScienceDaily (link)

Efficacy of Vitamin C Supplements in Prevention of Cancer: A Meta-Analysis of Randomized Controlled Trials (link)

(Very low dose!!)

Vitamin C Reduces Human Mortality - Life Extension (link)

Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis (link)