What Is It?
Carnitine is an amino acid-like compound that helps the body produce energy. While readily abundant in meats and dairy foods, some people take carnitine in supplement form to increase vitality. Carnitine transports fatty acids to the “factory” portion of cells, which then convert the fat into energy that the heart, muscles, and other body tissues can use.
Without enough carnitine to move fatty acids to the right place, your body will eventually wear down, and you may feel drained and tired. The heart in particular is highly dependent on carnitine, and taking it in supplement form is currently being explored as an option for speeding recovery after a heart attack as well as for treating angina (chest pain), arrhythmia (irregular heartbeats), and congestive heart failure.
Carnitine plays a critical role in metabolizing a number of other important substances as well, which helps to explain why it holds promise for so many disorders.
• Some studies indicate that carnitine may improve endurance in those weakened by disease, and boost an immune response in people who are HIV-infected.
• A form of carnitine that is produced naturally in the brain–acetyl-L-carnitine, or ALC–is currently being studied in supplement form as a possible treatment for memory loss associated with aging and Alzheimer’s disease.
• Studies are conflicting regarding the effectiveness of carnitine for enhancing athletic performance by improving energy and fat metabolism. A positive effect appears most pronounced for endurance-related events, such as cycling and long distance running.
Carnitine supplements are particularly valuable for people with conditions that can interfere with its absorption, including various liver and kidney problems, metabolic stress, long-term alcohol use, and in some cases, a high-fat diet. So check with your doctor if you have any concerns. A simple urine test can determine if you have a carnitine deficiency.
On supplement labels, amino acids are often prefaced with the letter L or the letter D. Purchase only the L-carnitine form, since it most resembles the carnitine produced naturally by the body.
There are no drug or nutrient interactions associated with carnitine.
• Higher than commonly recommended doses can apparently promote an unusual body odor. Ailments Dosage Alzheimer’s Disease 500 mg 3 times a day Angina 500 mg L-carnitine 3 times a day on an empty stomach Arrhythmia 500 mg L-carnitine 3 times a day Chronic Fatigue Syndrome 500-1,000 mg 3 times a day Congestive Heart Failure 1,000 mg (2 capsules) L-carnitine 2 or 3 times a day on an empty stomach Fibromyalgia 100 mg twice a day Heart Disease Prevention 500 mg L-carnitine twice a day Infertility, Male 2,000 mg L-carnitine 3 times a day Memory Loss/Impairment 500 mg twice a day with meals Weight Loss 500 mg L-carnitine 3 times a day
David Edelberg, MD