Methionine kinetics and balance at the 1985 FAO/WHO/UNU intake requirement in adult men studied with L-(2H3-methyl-1-13C)methionine as a tracer

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · American Journal of Clinical Nutrition; (United States)

OSTI ID:5462579

Young, V R; Wagner, D A; Burini, R; Storch, K J ^[1]

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1. Shriners Burns Institute, Boston, MA (USA)

The upper range of the requirement for methionine plus cystine in healthy adults was proposed in 1985 by FAO/WHO/UNU to be 13 mg.kg body wt-1.d-1. To explore the validity of this estimate, five healthy, young adult men were given for 7 d a diet based on an L-amino acid mixture supplying 13 mg methionine.kg-1.d-1 (87 mumol.kg-1.d-1) without cystine. Constant intravenous infusions of L-(2H3-methyl-1-13C)methionine were given on days 5 and 7 while subjects were in the fed and postabsorptive states, respectively. Estimates were made of methionine oxidation, and daily methionine balance was derived from the intake-oxidation data. For the five subjects, methionine balances were -0.9, +0.7, +3.5, -3.1, and -3.8 mg kg-1.d-1, or -6, +5, +23, -21, and -26 mumol.kg-1.d-1. These findings lead to the conclusion that the upper range of the requirement for methionine plus cystine probably exceeds 13 mg.kg-1.d-1 in healthy young adults. The implications of this conclusion for establishing an appropriate amount of sulfur amino acids in an amino acid requirement pattern for adults is discussed.

• OSTI ID: 5462579
• Journal Information: American Journal of Clinical Nutrition; (United States), Vol. 54:2; ISSN 0002-9165
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
METHIONINE
METABOLISM
ADULTS
CARBON 13
DEUTERIUM
MAN
NUTRITION
TRACER TECHNIQUES
AGE GROUPS
AMINO ACIDS
ANIMALS
CARBON ISOTOPES
CARBOXYLIC ACIDS
DRUGS
EVEN-ODD NUCLEI
HYDROGEN ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAMMALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PRIMATES
STABLE ISOTOPES
VERTEBRATES
550501* - Metabolism- Tracer Techniques