Carnitine : The Science Behind a Conditionally Essential Nutrient - v. 1033

Carnitine is a naturally occurring compound with a central role in intermediate metabolism.

This nutrient is widely used as a dietary supplement for its actions on fat metabolism, muscle performance, and cognitive function.

Several commercials promote its use by athletes and to combat obesity and aging without dose- or side-effect specifications, an issue of obvious public health relevance.

Approved medical indications for carnitine supplementation include primary (systemic or myopathic) carnitine deficiencies and secondary depletion states observed in organic acidemias, beta-oxidation, and respiratory chain defects and in chronic renal and heart failure.

Recent basic and clinical research supports a variety of beneficial effects of carnitine on the cardiovascular, immune, and nervous systems, on insulin resistance and obesity, apoptosis, and cancer. Clinical trials on its action in heart failure and peripheral arterial disease; in the lipodystrophy and neuropathy of HIV patients; in cancer-cachexia; in neurodegenerative disorders and the chronic fatigue syndrome; and in fertility, pregnancy, and premature neonates all show a wide range of potential applications for this natural nutrient, but have often led to contradictory results and