Leucine

Other Name(s):

a-amino-isocaproic acid

Unsubstantiated Claims:

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Leucine may improve healing of skin and bones, increase production of human growth hormone (HGH) and help control blood sugar.

Recommended Intake:

Amino acids (AAs) are available as individual AAs or in proprietary AA combinations, as well as part of multi-vitamin formulas, proteins, and food supplements. The forms include tablets, fluids, and powders. However, adequate protein in the diet should provide a sufficient source of all amino acids.

Leucine supplements should be taken together with valine and isoleucine.

There are no conditions that increase the requirements for leucine.

Side Effects, Toxicity and Interactions:

The use of a single amino acid supplement may lead to a negative nitrogen balance, decreasing metabolic efficiency and increasing workload in the kidneys. In children, taking single amino acid supplements may also harmfully affect growth parameters.

Very high doses may cause low blood sugar (hypoglycemia) and pellagra.

Always avoid taking individual amino acids in high dosage for prolonged periods.

Women who are pregnant or breast-feeding should not use leucine supplements.

Individuals who have maple syrup urine disease (MSUD), a rare inherited disorder, should avoid leucine and the other branched-chain amino acids (isoleucine and valine).

Additional Information:

Click here for a list of reputable Web sites with general information on nutrition.

References:

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2. Lide DR, Frederikse HPR, eds. Handbook of Chemistry and Physics. 75th ed. Boca Raton, FL: CRC Press, Inc.; 1994.

3. Murray RK, Granner DK, Mayes PA, Rodwell VW. Harper's Biochemistry. 25th ed. Stamford, CT: Appleton & Lange; 2000.

4. Meisenberg G, Simmons WH. Principles of Medical Biochemistry. Mosby Pub. Co.; 1998.

5. Styer L. Biochemistry. 4th ed. W.H. Freeman & Co.; 1995.

6. Montgomery R, Conway TW, Spector AA, Chappell D. Biochemistry: A Case-Oriented Approach. 6th ed. Mosby Pub. Co.; 1996.

7. Behrman RE, Kliegman RM, Nelson EE, Vaughan VC, eds. Nelson Textbook of Pediatrics. 14th ed. Philadelphia, PA: W.B. Saunders Co.; 1992.