Author
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Heird, William |
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Submitted to: Current Opinion in Clinical Nutrition and Metabolic Care
Publication Type: Review Article Publication Acceptance Date: 11/5/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Modern infant formulas contain sufficient indispensable as well as dispensable amino acids to support normal growth of term and preterm infants. However, current parenteral and specialized enteral amino acid preparations do not appear to be optimal. Many problems with parenteral preparations reflect the fact that ingested amino acids undergo more extensive enteric and hepatic metabolism than parenterally administered amino acids, including conversion to other amino acids which reach the plasma for support of ongoing protein synthesis. Since this important source of amino acids is bypassed when nutrients are delivered parenterally, parenteral requirements of these amino acids are increased. Also, while ingested phenylalanine and methionine appear to be converted to tyrosine and cyst(e)ine, respectively, parenterally administered phenylalanine and methionine are not. While glutamine, the branched-chain amino acids and arginine appear important in stressed infants and infants with compromised gastrointestinal function, specific roles have not been defined. Finally, since some amino acids are insoluble and/or unstable in aqueous solution, suitable ways to provide these amino acids are needed. Soluble dipeptides of all are safe and efficacious in adults; this likely is true for children, but data to prove this are lacking. More research is needed to define the optimal amino acid requirements of infants dependent on special nutrition regimens. |
