Effects of Different Vitamin C-Enriched Collagen Derivatives on Collagen Synthesis.
Level 2 - randomized trial
Randomized double-blind crossover trial
PubMed 30859848 · doi:10.1123/ijsnem.2018-0385
What was done
Ten recreationally active males participated in a randomized, double-blind crossover study comparing placebo against 15 g of vitamin C-enriched gelatin, hydrolyzed collagen (HC), or a gummy containing equal parts gelatin and HC. Supplements were consumed 1 hour before 6 minutes of jump rope exercise. Blood samples were collected before supplement consumption and 4 hours after exercise to assess N-terminal propeptide of procollagen, with a subset (n = 4) tested 1 hour post-ingestion for amino acid levels.
What was found
All active supplements produced similar increases in circulating amino acids. N-terminal propeptide of procollagen levels tended to increase by approximately 20% from baseline following gelatin and HC interventions, but not after placebo or gummy consumption. Large variability was observed, and no intervention reached statistical significance.
Why it matters
This trial compares different forms of vitamin C-enriched collagen taken prior to exercise, showing that while amino acid absorption occurs, measurable increases in collagen synthesis markers remain statistically unproven.
Limits
The sample size was very small (n = 10, with only n = 4 for amino acid kinetics) and restricted to recreationally active males. High inter-individual variability prevented statistically significant findings, and long-term functional or tissue adaptations were not assessed.