help button home button Endocrine Society JCEM
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

This Article
Right arrow Full Text (PDF)
Right arrow Submit a related Letter to the Editor
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Liel, Y.
Right arrow Articles by Shany, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Liel, Y.
Right arrow Articles by Shany, S.

Journal of Clinical Endocrinology & Metabolism, Vol 81, 857-859, Copyright © 1996 by Endocrine Society


ARTICLES

Evidence for a clinically important adverse effect of fiber-enriched diet on the bioavailability of levothyroxine in adult hypothyroid patients

Y Liel, I Harman-Boehm and S Shany
Department of Medicine, Soroka University Hospital of Kupat-Holim, Beer- Sheva, Israel. liel@bgumail.bgu.ac.il

To evaluate the effect of dietary fiber supplements on levothyroxine (T4) bioavailability in hypothyroid patients, dietary fiber-containing supplementation was withheld from patients requiring disproportionately high doses of T4, in whom a dietary history revealed ingestion of a dietary fiber supplement. The dose of T4 was maintained at a constant level. Serum thyrotropin (TSH) was assessed before and after removal of the dietary fiber supplements. T4 requirements, reflected by either decreased serum TSH or by decreased T4 dose, was observed in conjunction with decreased dietary fiber intake compared with T4 requirement during increased dietary fiber intake. In vitro experiments carried out to determine the mechanism of interaction between dietary fiber and T4 revealed dose dependent, nonspecific adsorption of levothyroxine by wheat bran. These results indicate a decrease in T4 bioavailability by dietary fiber through a mechanism involving nonspecific adsorption of T4 to dietary fibers. Increased intake of dietary fiber may account for the need for larger than expected doses of T4 in some hypothyroid patients.


This article has been cited by other articles:


Home page
JPEN J Parenter Enteral NutrHome page
A. Manessis, S. Lascher, P. Bukberg, T. Darmody, V. Yen, S. Sadek, and I. Young
Quantifying Amount of Adsorption of Levothyroxine by Percutaneous Endoscopic Gastrostomy Tubes
JPEN J Parenter Enteral Nutr, March 1, 2008; 32(2): 197 - 200.
[Abstract] [Full Text] [PDF]


Home page
J. Clin. Endocrinol. Metab.Home page
S. Checchi, A. Montanaro, L. Pasqui, C. Ciuoli, V. De Palo, M. C. Chiappetta, and F. Pacini
L-Thyroxine Requirement in Patients with Autoimmune Hypothyroidism and Parietal Cell Antibodies
J. Clin. Endocrinol. Metab., February 1, 2008; 93(2): 465 - 469.
[Abstract] [Full Text] [PDF]


Home page
JRSMHome page
G I Varughese, A A Tahrani, J Davis, R N Clayton, and F W F Hanna
Caveats in treating thyroid disease: practical implications
J R Soc Med, November 1, 2006; 99(11): 582 - 583.
[Full Text] [PDF]


Home page
Nutr Clin PractHome page
J. Boullata
Natural Health Product Interactions with Medication
Nutr Clin Pract, February 1, 2005; 20(1): 33 - 51.
[Abstract] [Full Text] [PDF]


Home page
Arch Fam MedHome page
K. A. Woeber
Update on the Management of Hyperthyroidism and Hypothyroidism
Arch Fam Med, August 1, 2000; 9(8): 743 - 747.
[Full Text] [PDF]


Home page
JAMAHome page
N. Singh, P. N. Singh, and J. M. Hershman
Effect of Calcium Carbonate on the Absorption of Levothyroxine
JAMA, June 7, 2000; 283(21): 2822 - 2825.
[Abstract] [Full Text] [PDF]


Home page
Arch Intern MedHome page
K. A. Woeber
Update on the Management of Hyperthyroidism and Hypothyroidism
Arch Intern Med, April 24, 2000; 160(8): 1067 - 1071.
[Abstract] [Full Text] [PDF]


Home page
J. Clin. Endocrinol. Metab.Home page
S. Peran, M. J. Garriga, G. Morreale de Escobar, M. Asuncion, and M. Peran
Increase in Plasma Thyrotropin Levels in Hypothyroid Patients during Treatment due to a Defect in the Commercial Preparation
J. Clin. Endocrinol. Metab., October 1, 1997; 82(10): 3192 - 3195.
[Abstract] [Full Text] [PDF]


Home page
JWatch GeneralHome page
FIBER MAY REDUCE ACTION OF LEVOTHYROXINE
Journal Watch (General), March 19, 1996; 1996(319): 7 - 7.
[Full Text]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1996 by The Endocrine Society