Muscular activity depends on your body's ability to convert fatty acids into
energy. Carnitine is an amino acid that is essential for this conversion. A
typical daily diet contains 5 to 100 mg of carnitine. The body produces
carnitine in the liver and kidneys and stores it in the skeletal muscles and
heart, as well as in sperm and in the brain. Some people cannot properly use carnitine from their diet or suffer from
dietary deficiencies of this nutrient. As a result, they may develop heart
disease, skeletal muscle weakness, or low blood sugar. If you experience these
symptoms and are found to have carnitine deficiency, your health care provider
may recommend use of the supplement levocarnitine, or L-carnitine.
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| Uses |
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L-carnitine offers a variety of potential therapeutic uses, primarily related
to the heart. - Preventing heart disease
- Improving heart function in people with congestive heart failure
- Reducing heart damage when taken soon after a heart attack
- Reducing the pain of angina
- Treating cardiac arrhythmia (irregular heartbeat) without affecting
blood pressure
- Reducing blood triglycerides and overall cholesterol levels while
increasing HDL, or good cholesterol.
Your health care provider may also recommend taking L-carnitine if you have
other health conditions, including the following: - Alcoholism
- Alzheimer's disease
- Anorexia
- Chronic fatigue syndrome
- Down's syndrome
- Hemodialysis
- Immunosuppression
- Male infertility
Carnitine may also be recommended as a weight-loss aid. |
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| Dietary Sources |
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Red meats are the primary dietary source of L-carnitine. Other animal-based
foods containing L-carnitine include fish, poultry, and milk products. Tempeh
(fermented soybeans), wheat, and avocados also contain this
nutrient. |
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| Other Forms |
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Carnitine is available as a supplement in several forms. Only the L-carnitine
forms are recommended. These include the following: - L-carnitine (LC), which is the most widely available, is the least
expensive, and has been studied the most
- L-acetylcarnitine (LAC), which appears to be best for Alzheimer's
disease and brain defects
- L-propionylcarnitine (LPC), which may be best for angina and other
heart problems
The D-carnitine form should not be used because it has produced undesirable
side effects. Certain L-carnitine products have been approved by the U.S. Food and Drug
Administration for medical use and are available only with your health care
provider's prescription. Others are sold as supplements and should not be used
to treat serious carnitine deficiency. |
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| How to Take It |
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Pediatric There is no specific dietary recommendation for carnitine. If laboratory
tests reveal that the child has an amino acid imbalance that requires treatment,
the healthcare provider may recommend a complete amino acid supplement that
contains carnitine. Adult Recommended doses of L-carnitine vary depending on the health condition being
treated. The following list provides guidelines for the most common
uses: - To improve fat metabolism and muscular performance: 1,000 to 2,000 mg
usually divided into two doses
- For treatment of heart disease: 600 to 1,200 mg three times daily, or
750 mg twice daily
- For treatment of alcohol-related deficiencies: 300 mg three times
daily
- For treatment of male infertility: 300 to 1,000 mg three times daily
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| Precautions |
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L-carnitine is not recommended for people with active liver or kidney
disease. If you take L-carnitine as a supplement to improve fat metabolism and
muscular performance, it is recommended that you skip using it one week each
month. If you take it in large quantities (5 g a day by an adult), you may
experience diarrhea. Additional research into the long-term safety of L-carnitine as a supplement
is needed. |
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| Possible Interactions |
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Blood levels of carnitine may be reduced by the anticonvulsant medication
valproic acid and may cause carnitine deficiency. Taking carnitine supplements
may prevent deficiency and may also reduce the side effects of valproic acid.
Please refer to the depletions monograph for more information. In a laboratory study, L-carnitine supplementation protected muscle tissue
against toxic side effects from treatment with AZT, a medication used to treat
AIDS. Additional studies are needed to confirm whether carnitine would also have
this effect in people. Consult with your healthcare practitioner before taking
carnitine supplements if you are currently taking AZT. Treatment with carnitine also protected heart cells against the toxic side
effects of doxorubicin, a chemotherapy medication, without reducing the
effectiveness of the chemotherapy in studies in both animals and children. If
you are currently being treated with doxorubicin, consult with your healthcare
provider about whether carnitine may be appropriate for you before you start
taking these supplements. |
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| Supporting Research |
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Brass EP, Hiatt WR. The role of carnitine and carnitine supplementation
during exercise in man and in individuals with special needs. J Am Coll
Nutr. 1998;17:207-215. Chung S, Cho J, Hyun T, et al. Alterations in the carnitine metabolism in
epileptic children treated with valproic acid. J Korean Med Soc.
1997;12:553-558. De Vivo DC, Bohan TP, Coulter DL, et al. L-Carnitine supplementation in
childhood epilepsy: current perspectives. Epilepsia.
1998;39:1216-1225. Elisaf M, Bairaaktari E, Katopodis K, et al. Effect of L-Carnitine
supplementation on lipid parameters in hemodialysis patients. Am J
Nephrol. 1998;18:416-421. Haas EM. Staying Healthy with Nutrition. Berkley, California:
Celestial Arts Publishing; 1992:65-79. Kelly GS. L-Carnitine: therapeutic applications of a conditionally-essential
amino acid. Alt Med Rev. 1998;3:345-60. Murray MT. Encyclopedia of Nutritional Supplements. Rocklin, Calif:
Prima Publishing; 1996:283-295. Murray MT, Pizzorno JE. Encyclopedia of Natural Medicine. 2nd ed.
Rocklin, Calif: Prima Publishing; 1996:206, 216, 246-247, 424, 505-506, 584. Newstrom H: Nutrients Catalog. Jefferson, NC: McFarland & Co.,
Inc.; 1993:103-105. Plioplys AV, Plioplys S. Amantadine and L-carnitine treatment of chronic
fatigue syndrome. Neuropsychobiology. 1997;35(1):16-23. Shils ME, Olson JA, Shike M, Ross AC. Modern Nutrition in Health and
Disease. 9th ed. Baltimore, Md: Williams & Wilkins; 1999: 90-92;
1377-1378. Van Wouwe JP. Carnitine deficiency during valproic acid treatment. Int J
Vit Nutr Res. 1995;65:211-214. Werbach MR. Nutritional Influences on Illness. 2nd ed. Tarzana, Calif:
Third Line Press; 1993:13-22, 655-671. |
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Copyright © 2003 OneMedicine
The publisher does not accept any responsibility for the accuracy of
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of any of the information contained herein, including any injury and/or damage
to any person or property as a matter of product liability, negligence, or
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guide to self-medication. The reader is advised to discuss the information
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regarding dosage, precautions, warnings, interactions, and contraindications
before administering any drug, herb, or supplement discussed
herein.
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