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Horm Metab Res 2005; 37(9): 566-571
DOI: 10.1055/s-2005-870424
Review
© Georg Thieme Verlag KG Stuttgart · New York

Effects of L-carnitine on Thyroid Hormone Metabolism and on Physical Exercise Tolerance

S.  Benvenga1
  • 1 Sezione di Endocrinologia del Dipartimento Clinico Sperimentale di Medicina e Farmacologia, University of Messina School of Medicine, and Programma di Endocrinologia Molecolare Clinica, Azienda Ospedaliera Universitaria Policlinico Gaetano Martino, 98125 Messina, Italy
Further Information

Publication History

Received 4 November 2004

Accepted after Revision 24 February 2005

Publication Date:
20 September 2005 (online)

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Abstract

L-carnitine (CARN) is a water-soluble, naturally occurring quaternary amine ubiquitous in biological fluids and animal tissues; in these tissues, CARN plays an important role in energy metabolism. Skeletal muscles store about 95 % of a total of 20 g CARN contained in the adult human body, but high-intensity physical exercise decreases the CARN muscle content. The daily allowance of CARN is mainly satisfied by diet. Keeping in mind important interstudy differences, the general conclusion is that CARN supplementation may enhance athletic performance when coupled to physical exercise itself. Healthy, essentially sedentary persons and untrained individuals do not benefit from supplementation, and certainly not if CARN is administered for a few days. CARN was also shown to modulate thyroid hormone action in peripheral tissues, the most frequent modulation observed being inhibition.

Key words

L-carnitine · Nutrients · Sports · Physical exercise · Thyroid hormone modulators

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Prof. Salvatore Benvenga

Sezione di Endocrinologia del Dipartimento Clinico Sperimentale di Medicina e Farmacologia, padiglione H, 4 piano

Policlinico Universitario Gaetano Martino · 98125 Messina · Italy

Phone: +39 (90) 221 35 17 or 3560

Fax: +39 (90) 221 35 18 or +39 (90) 69 39 17

Email: s.benvenga@me.nettuno.it