L-Carnitine

By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.

L-carnitine is a water-soluble amino acid-like compound found in foods such as lamb, beef, red meat, and pork. Your body also endogenously produces L-carnitine with the help of two amino acids – lysine and methionine – as well as Vitamins C and B6, iron, and niacin. In order to avoid L-carnitine deficiency, vegetarians should supplement and/or combine such foods as beans and rice, which contain lysine and methionine, respectively.

Like coenzyme Q10 (CoQ10), L-carnitine is also considered an antioxidant that protects your heart and blood vessels from oxidative stress that can lead to CAD. It helps prevent damage from toxic by-products which are generated through the metabolism of fats. As a vasodilator, L-carnitine opens blood vessels and increases blood flow to your heart, muscles and other tissues, resulting in better overall oxygen use by your body.

As a key nutrient for cardiac tissue, L-carnitine can serve as adjunctive treatment for conditions like angina, congestive heart failure (CHF), ventricular arrhythmia, and cholesterol disorders. It may be safely and effectively taken in combination with beta-blockers, ACE inhibitors, and other cardiac drugs for a more full-spectrum approach to symptom relief.

Health professionals can measure levels of L-carnitine in the blood to determine whether deficiency is at issue. Unfortunately, the body’s need for L-carnitine becomes most obvious in situations like heart disease, where the heart is energy-starved and may also lack CoQ10 and D-ribose. L-carnitine deficiency is also associated with renal insufficiency, lipid metabolic disorders and mitochondrial disorders.

Supplementation with L-carnitine is generally recommended for vegetarians or others who don’t get enough nutrients in their diets from which to synthesize it, and people over the age of forty. People taking pharmaceutical drugs like anticonvulsants, or patients with liver disease, kidney disease, or genetic defects related to L-carnitine metabolism may also lack L-carnitine. Classified as myopathic (reduced skeletal muscle concentrations) or systemic, L-carnitine deficiencies may respectively manifest through overt symptoms such as muscle cramps, muscle fatigue, and muscle pain following exercise, or subtle systemic symptoms such as impaired ventricular function.

L-carnitine is not very bioavailable. As there are various forms of L-carnitine, supplementation with a broad-spectrum product that contains L-carnitine fumarate, acetyl-L-carnitine, and propionyl-L-carnitine is the optimal choice. Because L-carnitine doesn’t get fully absorbed when taken orally, ingesting it in smaller doses 3 times per day on an empty stomach is the preferred method; I recommend starting with a low dose, then gradually increasing it until a desired effect is achieved:

  • 400 – 800 mg daily (especially for vegetarians) to prevent deficiency;
  • 500 -1,000 mg two-to-three times daily if you have coronary artery disease or angina;
  • 1 – 2 grams (sometimes up to 3 grams) daily for arrhythmia; and
  • 2 – 4 grams daily for congestive heart failure or following a heart attack.

© 2010 HeartMD Institute. All rights reserved.

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