Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

Effect of High-Dose vitamin C on hepatic cytochrome P450 3A4 activity

van Heeswijk, R.P.G., Cooper, C.L., Foster, B.C., Chauhan, B.M., Shirazi, F., Seguin, I., Phillips, E.J. and Mills, E. (2005) Effect of High-Dose vitamin C on hepatic cytochrome P450 3A4 activity. Pharmacotherapy, 25 (12). pp. 1725-1728.

Link to Published Version: http://dx.doi.org/10.1592/phco.2005.25.12.1725
*Subscription may be required

Abstract

Study Objectives. To investigate the effect of high-dose vitamin C on cytochrome P450 (CYP) 3A4 activity, and to evaluate possible sex-specific effects on CYP3A4 activity.

Design. Single-center longitudinal study.

Setting. Tertiary- and specialty-care teaching hospital.

Subjects. Fourteen healthy Caucasian adult volunteers (seven men, seven women).

Intervention. Subjects self-administered vitamin C 500 mg twice/day for 14 days.

Measurements and Main Results. Hepatic CYP3A4 activity was measured by using the erythromycin breath test on days 1 (baseline) and 15. Overall, no significant effect of vitamin C on CYP3A4 activity was observed. Sex and baseline results were significant predictors of changes in CYP3A4 activity. In men, mean activity increased by 21.9% (95% confidence interval −3.88–47.6%). The effect in women was not consistent.

Conclusion. Sex and baseline CYP3A4 activity appeared to influence the effect of vitamin C on CYP3A4 activity.

Item Type: Journal Article
Publisher: Wiley
Copyright: 2005 Pharmacotherapy Publications Inc.
URI: http://researchrepository.murdoch.edu.au/id/eprint/16032
Item Control Page Item Control Page