The Study
Differential effects of vitamin C or protandim on skeletal muscle adaptation to exercise.
This study looked at how vitamin C and a plant supplement affected muscle changes in a few rats and lab-grown mouse cells. It shows what happened in those animals under special conditions, but it doesn't prove that the same thing happens in people or even in all rats.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
When you exercise, your muscles make new proteins to get stronger — but taking big doses of vitamin C can block this process. A special plant-based supplement called Protandim doesn't block it — it helps.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 518 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — if you're trying to build endurance or muscle fitness through exercise, taking high-dose vitamin C supplements might reduce your gains, while natural antioxidant activators may help.
- 2Rats that ran and took vitamin C had 30-40% less new mitochondrial protein than rats that ran alone.
- 3Rats that took Protandim had the same or higher levels of new protein as those that ran without supplements.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of applied physiology
Year
2018
Authors
Danielle R Bruns, Sarah E. Ehrlicher, S. Khademi, L. Biela, F. Peelor, B. Miller, K. Hamilton
Related Content
Claims (6)
Taking high doses of vitamin C and E supplements reduces the body's physiological adaptations to exercise by blocking the signaling triggered by oxidative stress.
In adult male Sprague-Dawley rats that run voluntarily, taking 500 mg/kg of vitamin C daily for three weeks reduces the increase in mitochondrial protein synthesis that normally occurs in soleus and plantaris muscles after exercise.
In adult male Sprague-Dawley rats performing endurance exercise, vitamin C supplements do not change the rate of DNA synthesis in skeletal muscle, and this shows that vitamin C's reduction of mitochondrial protein synthesis is not caused by a decrease in cell division.
In adult male Sprague-Dawley rats that exercise voluntarily, daily intake of 600 ppm Protandim for six weeks increases mitochondrial protein synthesis and improves cellular protein balance, while maintaining redox signaling.
In mouse muscle cells under oxidative stress, Protandim increases the rate of protein production relative to DNA production, showing that protein maintenance mechanisms are activated without increasing cell division.
In mouse muscle cells under oxidative stress, vitamin C lowers the rate of protein synthesis without changing the rate of DNA synthesis.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.