Tyrosine requirement during the rapid catch-up growth phase of recovery from severe childhood undernutrition.

Abstract

The requirement for aromatic amino acids during the rapid catch-up in weight phase of recovery from severe childhood undernutrition (SCU) is not clearly established. As a first step, the present study aimed to estimate the tyrosine requirement of children with SCU during the catch-up growth phase of nutritional rehabilitation using a diet enriched in energy and proteins. Tyrosine requirement was calculated from the rate of excretion of ¹³CO2 (F ¹³CO2) during [¹³C]phenylalanine infusion in thirteen children with SCU, five females and eight males, at about 19 d after admission when the subjects were considered to have entered their rapid catch-up growth phase and were consuming 627.3 kJ and about 3.5 g protein/kg per d. Measurements of F ¹³CO2 during [¹³C]phenylalanine infusion were made on two separate days with a 1 d interval. Three measurements at tyrosine intakes of 48, 71 and 95 mg/kg per d were performed on experimental day 1 and measurements at tyrosine intakes of 148, 195 and 241 mg/kg per d were performed on experimental day 2. An estimate of the mean requirement was derived by breakpoint analysis with a two-phase linear regression cross-over model. The breakpoint, which represents an estimate of the mean tyrosine requirement, is a value of 99 mg/kg per d when the children were growing at about 15 g/kg per d. The result indicates that the mean requirement for tyrosine during the catch-up growth phase of SCU is about 99 mg/kg per d under similar conditions to the present study.

• Authors: Asha Badaloo, Jean W-C Hsu, Carolyn Taylor-Bryan, Marvin Reid, Terrence Forrester, Farook Jahoor
• Journal: The British journal of nutrition (Br J Nutr) Vol. 104 Issue 8 Pg. 1174-80 (Oct 2010) ISSN: 1475-2662 [Electronic] England
• PMID: 20550742 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Carbon Isotopes
• Tyrosine
• Phenylalanine

Topics

• Carbon Isotopes
• Female
• Humans
• Infant
• Infant Food
• Infant Nutrition Disorders (diet therapy, metabolism)
• Male
• Malnutrition (diet therapy)
• Nutritional Requirements
• Phenylalanine (chemistry, metabolism)
• Tyrosine (metabolism)