High-dose intravenous vitamin C is not associated with an increase of pro-oxidative biomarkers.
Eur J Clin Nutr
; 58(8): 1151-8, 2004 Aug.
Article
em En
| MEDLINE
| ID: mdl-15054428
ABSTRACT
OBJECTIVE:
High-dose vitamin C therapy might mediate beneficial clinical effects by counteracting reactive oxygen species. However, concerns are raised whether this approach might provoke diametrical (ie pro-oxidative) effects. The objective was to determine ascorbyl free radical (AFR) concentrations and potential variables of pro-oxidative damage.DESIGN:
Crossover study; six healthy males received daily infusions of 750 or 7500 mg vitamin C for six consecutive days. Fasting concentrations of vitamin C and AFR were determined daily. On day 1, concentrations of vitamin C and AFR were measured at 0.25, 0.5, 1, 2, 4 and 8 h post infusion. Plasma concentrations of thiobarbituric acid-reactive substances (TBARS), tocopherol and urine concentrations of 8-oxoguanosine were determined on days 1 and 6.RESULTS:
Kinetic studies on day 1 showed that concentrations of vitamin C and AFR displayed parallel dose- and time-dependent kinetics and elimination was highly efficient. Vitamin C and AFR fasting concentrations on days 2-6 were slightly above the baseline, suggesting new, stable steady states. TBARS decreased in both groups, whereas tocopherol and 8-oxoguanosine concentrations remained unchanged.CONCLUSION:
Kinetics of AFR largely depend on plasma vitamin C concentrations and AFR is eliminated efficiently. Our data do not support induction of pro-oxidative effects in healthy volunteers given intravenous high-dose vitamin C. SPONSORSHIP Pascoe Pharmazeutische Präparate GmbH, Giessen, Germany.
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Base de dados:
MEDLINE
Assunto principal:
Ácido Ascórbico
/
Espécies Reativas de Oxigênio
/
Radicais Livres
/
Guanosina
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article