In a healthy adult with a ligament injury, does vitamin C improve ligament healing and what dose is appropriate?

Vitamin C and Ligament Recovery

Vitamin C supplementation at 1000 mg three times daily (3 g/day total) can support ligament healing by serving as an essential cofactor for collagen synthesis, though the clinical evidence for accelerated recovery in humans remains limited.

Mechanism Supporting Ligament Healing

• Vitamin C is an essential cofactor/cosubstrate for collagen synthesis, which forms the structural foundation of ligaments and is critical for tissue repair after injury 1
• The vitamin functions as a potent antioxidant that scavenges free radicals and mitigates oxidative stress during the inflammatory phase of healing 1
• Vitamin C protects endothelial function and maintains barrier integrity, which supports the vascular supply necessary for tissue regeneration 1

Evidence from Preclinical Studies

• Animal studies demonstrate that high-dose vitamin C (150 mg every 2 days in rats) significantly accelerates tendon healing through enhanced angiogenesis, increased type I collagen production, and greater collagen fiber diameter 2
• Preclinical research shows vitamin C supplementation increases type I collagen synthesis and reduces oxidative stress parameters in ligament and tendon models 3
• One animal study of ACL reconstruction showed significant short-term improvements (1-6 weeks) in graft incorporation with vitamin C, though long-term differences (42 weeks) were not sustained 3

Human Clinical Evidence: Limited but Suggestive

• A systematic review found no high-quality human trials demonstrating accelerated ligament healing with vitamin C supplementation compared to controls 3
• One human study of ACL surgery patients found that vitamin E and C supplementation did not improve muscle strength recovery or prevent atrophy over 3 months post-surgery 4
• However, the same study revealed that baseline plasma vitamin C levels correlated significantly (r=0.59, P=0.006) with subsequent strength improvement, suggesting that adequate vitamin C status—rather than short-term supplementation—may be more important 4
• A 2017 study showed that vitamin C-enriched gelatin (15 g) taken 1 hour before exercise doubled markers of collagen synthesis in healthy subjects, indicating that vitamin C can augment collagen production when combined with mechanical loading 5

Recommended Dosing for Ligament Injury

• The appropriate dose is 1000 mg three times daily (3 g/day total), divided to maximize intestinal absorption 1
• This dosing aligns with guideline recommendations for repletion during inflammatory states and major tissue injury 1
• Dividing the total daily dose into three separate administrations (1000 mg TID) helps overcome saturable intestinal transporters that limit absorption at higher single doses 1, 6
• Treatment should continue throughout the acute healing phase, typically 2-4 weeks or until adequate wound healing is achieved 1

Practical Considerations and Caveats

• Oral vitamin C absorption is limited by saturable intestinal transporters, particularly at doses above 200 mg per administration; dividing doses maximizes bioavailability 1, 6
• Plasma vitamin C levels decline rapidly during inflammation, making patients with acute injuries functionally deficient despite normal dietary intake 1, 7
• Very high doses (>10 g/day) may cause gastrointestinal side effects such as diarrhea, though 3 g/day is well below this threshold 1
• Contraindications include hemochromatosis, G6PD deficiency, active oxalate kidney stones, and severe renal impairment due to enhanced iron absorption and increased oxalate excretion 1, 7

Clinical Bottom Line

• While vitamin C is biologically essential for collagen synthesis and animal data are encouraging, human clinical trials have not yet demonstrated that supplementation accelerates functional recovery from ligament injuries 3, 4
• The strongest human evidence suggests that maintaining adequate baseline vitamin C status through long-term dietary habits is more effective than short-term high-dose supplementation 4
• Given the excellent safety profile at 3 g/day and the theoretical benefit for collagen synthesis, vitamin C supplementation is reasonable during the acute healing phase (first 2-4 weeks post-injury), though expectations should be tempered by the lack of robust clinical evidence 1, 3
• Patients should be counseled that vitamin C is a supportive measure rather than a proven intervention for accelerated ligament healing 3, 8