Carnitine

• Method of Action

• Food Sources

Description

Carnitine is a nonessential amino acid, which means that it is manufactured from other amino acids in the liver; it does not have to be obtained directly through the diet.

In humans, carnitine deficiencies result in the buildup of acid metabolites in tissues and increased levels of triglycerides, a type of fat in the blood. Carnitine deficiencies also lead to poor energy production in the heart and poor metabolism of fats. Dr. Eman Cameron has recently suggested that carnitine deficiency may also account for the muscle wasting, weakness, and poor sense of well-being in a cancer patient. Supplementation with lysine and vitamin C may help correct a low carnitine level.

The role of carnitine in fat metabolism is to help transport free fatty acids into the mitochondria of cells where the fats can be used as a source of energy. Carnitine has also been found to be important in the synthesis and function of sperm in the testes. In male animals, carnitine deficiency can result in infertility.

Method of Action

Carnitine is synthesized in the body from the essential amino acid lysine. The conversion of lysine to carnitine in all cells of the body is dependent upon adequate vitamin C levels. It has been estimated that about 0.1 percent of the dietary lysine is converted to carnitine in the body. Carnitine is not found in a vegetable-based diet; it is only found in animal products. Therefore, vegetarians who may consume a lysine-deprived diet may have insufficient amounts of carnitine. Animals fed a wheat gluten diet low in lysine and carnitine have significantly lower levels of carnitine in their hearts and skeletal muscles.

Recently, medical studies in Japan and Europe have indicated that carnitine supplementation can help lower triglycerides in individuals with elevated blood fats. Doses used are between 400 and 2,000 mg per day of L-carnitine.

D,L-carnitine (the synthetic derivative) has also been found useful in lowering triglycerides, but may have a more significant problem with liver toxicity associated its excessive use.

Preliminary reports indicate that carnitine may be useful for extending endurance in athletes who are engaged in long-term exercise. Carnitine has also been used to treat acid buildup in the blood of diabetics (ketoacidosis).

Food Sources

Carnitine is a nonessential amino acid, which means that it is manufactured from other amino acids in the liver; it does not have to be obtained directly through the diet.