The effects of vitamin C and E on exercise-induced physiological adaptations: a systematic review and Meta-analysis of randomized controlled trials
What this study found
Vitamin C and/or vitamin E did not meaningfully blunt training adaptations. Pooled effects were null for VO2max (SMD -0.14, 95% CI -0.43 to 0.15, P = 0.35), endurance performance (SMD -0.01, 95% CI -0.38 to 0.36, P = 0.97), lean mass (SMD -0.07, 95% CI -0.36 to 0.23, P = 0.67), and muscle strength (SMD -0.15, 95% CI -0.16 to 0.46, P = 0.35). Age did not modify the results, and adverse events were not reported.
- Study & population
- Systematic review and meta-analysis of randomized controlled trials in adults undergoing supervised aerobic or resistance training.
- Intervention
- Oral vitamin C and/or vitamin E supplementation was given alongside supervised exercise training, most commonly vitamin C 1000 mg/day and vitamin E 400 IU/day.
- Key limitation
- The evidence base was small, with modest numbers of participants across outcomes and variable supplement regimens and training protocols.
View source
Open PDFOriginal abstract
Abstract We conducted a systematic review and meta-analysis of randomized controlled trials examining the effect of vitamin C and/or E on exercise-induced training adaptations. Medline, Embase and SPORTDiscus databases were searched for articles from inception until June 2019. Inclusion criteria was studies in adult humans where vitamin C and/or E had to be consumed alongside a supervised exercise training program of ≥4 weeks. Nine trials were included in the analysis of aerobic exercise adaptations and nine for resistance training (RT) adaptations. Vitamin C and/or E did not attenuate aerobic exercise induced improvements in maximal aerobic capacity (O2max) (SMD −0.14, 95% CI: −0.43 to 0.15, P = 0.35) or endurance performance (SMD −0.01, 95% CI: −0.38 to 0.36, P = 0.97). There were also no effects of these supplements on lean mass and muscle strength following RT (SMD −0.07, 95% CI: −0.36 to 0.23, P = 0.67) and (SMD −0.15, 95% CI: −0.16 to 0.46, P = 0.35), respectively. There was also no influence of age on any of these outcomes (P > 0.05). These findings suggest that vitamin C and/or E does not inhibit exercise-induced changes in physiological function. Studies with larger sample sizes and adequate power are still required.