Background/Aim: L-Ascorbic acid (AA) is the predominant circulating form of vitamin C found in human blood. It has been hypothesized that surgical stress increases the vitamin C metabolite dehydroascorbic acid (DHAA). Vitamin C is mainly excreted through the kidneys. In this study, the ratio of AA to DHAA excreted in urine was determined in patients who had undergone total hip joint endoprosthesis surgery (n = 12), and the results were compared with data obtained from healthy controls (n = 12). Methods: All subjects received 1,000 mg sodium ascorbate intravenously three times a day (every 8 h) for 8 days, starting 2 days prior to surgery. Total urine was collected daily while subsequent determinations of AA and DHAA were performed photometrically. Results: Administration of vitamin C led to average daily excretions of the combined products AA + DHAA of 2,343 ± 438 mg/day (mean value ± confidence intervals). The initial average ratio DHAA/AA of all 24 probands was 0.064 (6% DHAA; 153 ± 76 mg/day). One day after surgery, an increase in the DHAA/AA ratio to 0.165 (15% DHAA; 332 ± 107 mg/day) was measured in the patients. The ratio decreased 2 days after surgery and returned to normal within 5 days. Conclusion: Our data indicate that surgery increases the oxidation of AA and urinary excretion of DHAA, as a result of the enhanced formation of free radicals.

Keywords:
Vitamin C supplements, Ascorbic acid, Dehydroascorbic acid, Surgical stress
This content is only available via PDF.
© 2003 S. Karger AG, Basel
2003
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.