Vitamin C and fatigue
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Vitamin C and Fatigue: Clinical Evidence and Mechanisms
Intravenous Vitamin C and Fatigue Reduction
Multiple clinical studies have shown that intravenous (IV) vitamin C can significantly reduce fatigue in various populations. In a randomized controlled trial with healthy office workers, a single high dose of IV vitamin C led to a rapid and sustained reduction in fatigue scores compared to placebo, with effects lasting at least one day. This benefit was especially notable in individuals with lower baseline vitamin C levels, and no significant adverse effects were reported . Similarly, systematic reviews of IV vitamin C in patients with fatigue from different causes—including post-viral fatigue and long COVID—found that most controlled and observational studies reported significant decreases in fatigue after treatment. These studies also noted improvements in related symptoms such as sleep disturbances, concentration, depression, and pain 210.
Oral Vitamin C Supplementation and Mental Vitality
Oral vitamin C supplementation has also been linked to improvements in mental vitality. In a randomized controlled trial with young adults who had low vitamin C status, supplementation increased attention and work engagement, with a trend toward reduced fatigue. However, the effect on mood was less clear, and the most consistent benefit was seen in cognitive performance and attentional focus . Animal studies further support the anti-fatigue effects of vitamin C, showing that it can reduce biochemical markers of fatigue and oxidative stress, with a stronger effect than taurine in some cases .
Vitamin C in Combination with Other Nutrients
Some studies have explored the effects of vitamin C combined with other nutrients. For example, a supplement containing pomegranate extract, B vitamins, and vitamin C was associated with significant improvements in prolonged fatigue among healthy consumers, with good tolerability and no reported adverse effects . In adults with long COVID, a combination of l-arginine and vitamin C improved physical performance, muscle strength, endothelial function, and reduced persistent fatigue compared to placebo .
Mechanisms: Antioxidant, Anti-Inflammatory, and Metabolic Support
The beneficial effects of vitamin C on fatigue are thought to be related to its antioxidant and anti-inflammatory properties, as well as its role in supporting energy metabolism and reducing oxidative stress. Vitamin C helps regulate oxidative stress and inflammation, both of which are implicated in the development of fatigue, especially in chronic illnesses and post-viral syndromes 279. Reviews highlight that adequate vitamin C status is essential for energy production, neuronal function, and overall cellular health, all of which contribute to reduced feelings of fatigue 79.
Systematic Reviews and Meta-Analyses
Systematic reviews and meta-analyses confirm that vitamin C supplementation—both oral and intravenous—has a statistically and clinically significant effect in reducing fatigue across different populations, including those with chronic illnesses and healthy individuals. These reviews also suggest improvements in sleep quality and endothelial function, further supporting the role of vitamin C in managing fatigue 59.
Conclusion
The current body of research indicates that vitamin C, especially when administered intravenously or in combination with other nutrients, can effectively reduce fatigue in both healthy individuals and those with chronic or post-viral conditions. The benefits are likely due to vitamin C’s antioxidant, anti-inflammatory, and metabolic support roles. While more research is needed to refine dosing and identify which populations benefit most, vitamin C appears to be a safe and promising option for managing fatigue 12345678+2 MORE.
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