High-dose intravenous vitamin C is not associated with an increase of pro-oxidative biomarkers.
Level 2 - randomized trial
Randomized crossover clinical trial
PubMed 15054428 · doi:10.1038/sj.ejcn.1601943
What was done
In a crossover trial, six healthy male volunteers received daily intravenous infusions of either 750 mg or 7500 mg vitamin C for six consecutive days. Fasting plasma concentrations of vitamin C and ascorbyl free radicals (AFR) were measured daily, with detailed pharmacokinetic sampling on day 1 at 0.25, 0.5, 1, 2, 4, and 8 hours post-infusion. Markers of oxidative stress—plasma thiobarbituric acid-reactive substances (TBARS), plasma tocopherol, and urinary 8-oxoguanosine—were measured on days 1 and 6.
What was found
The abstract reports no exact numerical values or statistical parameters. AFR concentrations showed dose- and time-dependent kinetics matching vitamin C clearance. Fasting vitamin C and AFR concentrations on days 2 to 6 remained slightly above baseline, indicating a new steady state. Plasma TBARS decreased in both dosing groups, while plasma tocopherol and urinary 8-oxoguanosine concentrations were unchanged from baseline.
Why it matters
These findings suggest that high-dose intravenous vitamin C does not provoke systemic pro-oxidative damage in healthy volunteers, supporting its short-term safety profile regarding oxidative stress.
Limits
The sample size is extremely small (n = 6) and restricted solely to healthy males, limiting generalizability to clinical populations with elevated baseline oxidative stress. The abstract reports no numerical values, confidence intervals, or p-values. The study was supported by a vitamin C pharmaceutical manufacturer.
Cited by
- supports Successive treatments with high-dose intravenous vitamin C have not been shown to increase pro-oxidative markers in healthy individuals.