Effects of oral L-carnitine supplementation on in vivo long-chain fatty acid oxidation in healthy adults

• Published in: Metabolism, clinical and experimental Vol. 51; no. 11; pp. 1389 - 1391
• Main Authors: M[uuml ]ller, D.M., Seim, H., Kiess, W., L[ouml ]ster, H., Richter, T.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.11.2002; Elsevier
• Subjects: Administration, Oral; Adult; Biological and medical sciences; Blood Glucose - metabolism; Breath Tests; Carbon Dioxide - analysis; Carbon Isotopes; Carnitine - administration & dosage; Carnitine - pharmacokinetics; Carnitine - pharmacology; Fatty Acids - metabolism; Female; General and cellular metabolism. Vitamins; Glycated Hemoglobin A - metabolism; Humans; Lipids - blood; Male; Medical sciences; Oxidation-Reduction; Pharmacology. Drug treatments; Reference Values; Human; Healthy subject; Long chain; Treatment efficiency; Lipids; Levocarnitine; Fatty acids; In vivo; Diet therapy; Adult; Oxidation; Supplementation; Food supplement
• ISSN: 0026-0495; 1532-8600
• DOI: 10.1053/meta.2002.35181

Despite an abundance of literature describing the basic mechanisms of action of L-carnitine metabolism, there remains some uncertainty regarding the effects of oral L-carnitine supplementation on in vivo fatty acid oxidation in normal subjects under normal conditions. It is well known that L-carnitine normalizes the metabolism of long-chain fatty acids in cases of carnitine deficiency. However, it has not yet been shown that L-carnitine influences the metabolism of long-chain fatty acids in subjects without disturbances in fatty acid metabolism. Therefore, we investigated the effects of oral L-carnitine supplementation on in vivo long-chain fatty acid oxidation by measuring 1-[13C] palmitic acid oxidation in healthy subjects before and after L-carnitine supplementation (3 [times ] 1 g/d for 10 days). We observed a significant increase in 13CO2 exhalation. This is the first investigation to conclusively demonstrate that oral L-carnitine supplementation results in an increase in long-chain fatty acid oxidation in vivo in subjects without L-carnitine deficiency or without prolonged fatty acid metabolism.