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Lysine requirement in healthy school‐aged children determined by indicator amino acid oxidation method
Author(s) -
Elango Rajavel,
Humayun Mohammad A,
Ball Ronald O,
Pencharz Paul B
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a333-a
Subject(s) - lysine , phenylalanine , population , energy requirement , crossover study , zoology , amino acid , protein requirement , urine , chemistry , biology , biochemistry , medicine , regression , mathematics , statistics , alternative medicine , environmental health , pathology , body weight , placebo
Lysine (LYS) requirement in school‐aged children was determined by the indicator amino acid oxidation (IAAO) method. Five, healthy children (7 – 9.5 yr) randomly received each of seven dietary levels of LYS (5, 15, 25, 35, 50, 65 and 80 mg/kg/d) as part of an isocaloric and isonitorgenous diet. The diet provided energy at 1.7 X REE and protein at 1.5 g/kg/d based on egg protein composition. LYS requirement was determined by measuring the oxidation of L‐[1‐ 13 C]‐phenylalanine to 13 CO 2 ( F 13 CO 2 ). Breath and urine samples were collected at baseline and isotopic steady state. Linear regression crossover analysis identified a breakpoint (requirement) at minimal F 13 CO 2 in response to different LYS intakes. The mean and population‐safe LYS requirements were determined to be 35.2 and 58.1 mg/kg/d respectively. These results are similar to the mean and population‐safe LYS requirements of 36.6 and 52.5 mg/kg/d, respectively in adult humans (Kriengsinyos, Ball, Pencharz et al, 2002).These results probably do not reflect the additional lysine required for growth due to the short duration of the IAAO study. This suggests that the maintenance needs for LYS are similar in children and adults. Therefore the factorial method applied to determine LYS requirements in children is valid. (CIHR supported). 1Phenylalanine oxidation ( F 13 CO 2 , μmol/kg/hr) in response to graded lysine intakes