Elsevier

Free Radical Biology and Medicine

Volume 77, December 2014, Pages 130-138
Free Radical Biology and Medicine

Original Contribution
High-dose vitamin C supplementation increases skeletal muscle vitamin C concentration and SVCT2 transporter expression but does not alter redox status in healthy males

https://doi.org/10.1016/j.freeradbiomed.2014.09.013Get rights and content

Highlights

  • Healthy males were supplemented with high-dose oral vitamin C or placebo for 42 days.

  • Skeletal muscle biopsies were taken on days 0, 1, 7, and 42 in crossover trials.

  • Skeletal muscle vitamin C, redox markers, and SVCT2 expression were measured.

  • Skeletal muscle vitamin C concentration increased significantly by 7 days.

  • Oral vitamin C increased SVCT2 protein expression, but did not alter redox measures.

Abstract

Antioxidant vitamin C (VC) supplementation is of potential clinical benefit to individuals with skeletal muscle oxidative stress. However, there is a paucity of data reporting on the bioavailability of high-dose oral VC in human skeletal muscle. We aimed to establish the time course of accumulation of VC in skeletal muscle and plasma during high-dose VC supplementation in healthy individuals. Concurrently we investigated the effects of VC supplementation on expression levels of the key skeletal muscle VC transporter sodium-dependent vitamin C transporter 2 (SVCT2) and intramuscular redox and mitochondrial measures. Eight healthy males completed a randomized placebo-controlled, crossover trial involving supplementation with ascorbic acid (2×500 mg/day) over 42 days. Participants underwent muscle and blood sampling on days 0, 1, 7, and 42 during each treatment. VC supplementation significantly increased skeletal muscle VC concentration after 7 days, which was maintained at 42 days (VC 3.0±0.2 (mean±SEM) to 3.9±0.4 mg/100 g wet weight (ww) versus placebo 3.1±0.3 to 2.9±0.2 mg/100 g ww, p=0.001). Plasma VC increased after 1 day, which was maintained at 42 days (VC 61.0±6.1 to 111.5±10.4 µmol/L versus placebo 60.7±5.3 to 59.2±4.8 µmol/L, p<0.001). VC supplementation significantly increased skeletal muscle SVCT2 protein expression (main treatment effect p=0.006) but did not alter skeletal muscle redox measures or citrate synthase activity. A main finding of our study was that 7 days of high-dose VC supplementation was required to significantly increase skeletal muscle vitamin C concentration in healthy males. Our findings implicate regular high-dose vitamin C supplementation as a means to safely increase skeletal muscle vitamin C concentration without impairing intramuscular ascorbic acid transport, antioxidant concentrations, or citrate synthase activity.

Section snippets

Subjects

Healthy male participants (n=8) ages 18–40 years were recruited for the study through local community- and university-wide advertising. Potential participants completed a prior medical screening session and questionnaire to rule out any cardiovascular, pulmonary, renal, or metabolic disease. Individuals were excluded if they were smokers, if they suffered from a bleeding disorder or heart murmur, if they were highly trained athletes, or if they were consuming any vitamin supplements. This study

Participants

All eight enrolled participants completed the trial as outlined. Participants were aged 25.9±2.3 years and had a mean height and weight of 178.9±3.8 cm and 81.8±4.2 kg, respectively. Baseline plasma vitamin C concentrations of participants were 58.1±6.7 µmol/L, and skeletal muscle concentrations were 2.9±0.2 mg/100 g wet weight. All participants had adequate baseline plasma vitamin C concentrations according to plasma cutoff levels reported by Jacob and Sotoudeh [37]. Baseline skeletal muscle

Discussion

A major finding of the present study was that 7 days of supplementation with vitamin C (500 mg twice daily) was required for vitamin C concentrations in skeletal muscle to significantly increase in healthy males with adequate baseline vitamin C concentrations. Vitamin C concentration did not increase further in skeletal muscle after 7 days of vitamin C supplementation, although the increase compared to placebo was greatest (~1.3 times placebo) at 42 days. In contrast, plasma vitamin C was more

Acknowledgments

We gratefully thank our medical doctor, Dr. Andrew Garnham, for his medical support and consultation throughout the trial, as well as for performing all muscle biopsy and blood collection procedures.

References (50)

  • M.C. Gomez-Cabrera et al.

    Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance

    Am. J. Clin. Nutr.

    (2008)
  • L. Wechtersbach et al.

    Reduction of dehydroascorbic acid at low pH

    J. Biochem. Biophys. Methods

    (2007)
  • J.P. Mollica et al.

    Are genuine changes in protein expression being overlooked? Reassessing Western blotting

    Anal. Biochem.

    (2009)
  • Y. Fu et al.

    Chronic ginseng consumption attenuates age-associated oxidative stress in rats

    J. Nutr.

    (2003)
  • A. Gomes et al.

    Fluorescence probes used for detection of reactive oxygen species

    J. Biochem. Biophys. Methods

    (2005)
  • P.A. Srere

    Citrate synthase: [EC 4.1.3.7. Citrate oxaloacetate-lyase (CoA-acetylating)]

    Methods Enzymol.

    (1969)
  • P.K. Smith et al.

    Measurement of protein using bicinchoninic acid

    Anal. Biochem.

    (1985)
  • A. Amano et al.

    Ascorbic acid depletion enhances expression of the sodium-dependent vitamin C transporters, SVCT1 and SVCT2, and uptake of ascorbic acid in livers of SMP30/GNL knockout mice

    Arch. Biochem. Biophys.

    (2010)
  • Y. Kishimoto et al.

    Ascorbic acid enhances the expression of type 1 and type 4 collagen and SVCT2 in cultured human skin fibroblasts

    Biochem. Biophys. Res. Commun.

    (2013)
  • M.E. Meredith et al.

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

    Biochem. Biophys. Res. Commun.

    (2011)
  • I. Savini et al.

    Redox regulation of vitamin C transporter SVCT2 in C2C12 myotubes

    Biochem. Biophys. Res. Commun.

    (2007)
  • F. McArdle et al.

    UVR-induced oxidative stress in human skin in vivo: effects of oral vitamin C supplementation

    Free Radic. Biol. Med.

    (2002)
  • Y. Tamari et al.

    Protective roles of ascorbic acid in oxidative stress induced by depletion of superoxide dismutase in vertebrate cells

    Free Radic. Res.

    (2013)
  • B. Frei et al.

    Ascorbate is an outstanding antioxidant in human blood plasma

    Proc. Natl. Acad. Sci. USA

    (1989)
  • E.J. Anderson et al.

    Mitochondrial H2O2 emission and cellular redox state link excess fat intake to insulin resistance in both rodents and humans

    J. Clin. Invest.

    (2009)
  • Cited by (21)

    • SVCT2–mediated ascorbic acid uptake buffers stress responses via DNA hydroxymethylation reprogramming of S100 calcium-binding protein A4 gene

      2022, Redox Biology
      Citation Excerpt :

      These results indicate that the deficits in SVCT2-dependent ascorbic acid uptake in the mPFC may confer to the pathophysiology of depression. Previous reports have indicated that a high level of exogenous ascorbic acid may restore SVCT2 expression in a positive feedback-dependent manner [46]. To demonstrate the effect of ascorbic acid on SVCT2 expression, SVCT2 protein levels were measured in the mPFC of mice that received intraperitoneal injection of ascorbic acid ranging from 10 mg/kg to 1000 mg/kg.

    • Vitamin C

      2020, Present Knowledge in Nutrition: Basic Nutrition and Metabolism
    • Muscle redox signalling pathways in exercise. Role of antioxidants

      2016, Free Radical Biology and Medicine
      Citation Excerpt :

      Unfortunately, there is a paucity of studies specifically investigating effects of chronic vitamin C supplementation in isolation of other antioxidants on force production during exercise in healthy individuals. Moreover, given that it might take up to seven days of supplementation with high dose oral vitamin C (1 g/day) to significantly increase muscle vitamin C concentrations [131], it is unclear what effect an acute dose would have in muscle. Acute vitamin C infusion (2 g) was shown to improve knee extensor fatigue resistance during repetitive exhaustive knee extensions in patients with chronic obstructive pulmonary disease (COPD), as demonstrated by improved maintenance of maximal and magnetic femoral nerve stimulated knee extensor force production [136].

    View all citing articles on Scopus
    View full text