Lysine requirement through the human life cycle.
Lysine cannot be synthesized by mammals and, as a consequence, is an indispensable amino acid. The main role of lysine is to participate in protein synthesis. The catabolism of lysine is principally located in the liver. Lysine released from digested protein undergoes a significant first-pass metabolism of approximately 30 to 42% in humans and piglets. An important question regarding the biological basis of the requirement of lysine is the possible participation of microbial de novo synthesized amino acids in the whole-body fluxes. Recent intake recommendations to meet the lysine requirement range from 64 to 30 mg/(kg.d) for 0.5-y infants and adults (>18 y), respectively. Lysine intake in the Western human diet is in the range 40-180 mg/(kg.d). An upper limit of 300-400 mg/(kg.d) can be considered in humans.
Tomé
Daniel
D
INRA, AgroParisTech, UMR914 Nutrition Physiology and Ingestive Behaviour, F-75005 Paris, France. tome@agroparistech.fr
Bos
Cécile
C
D000367:Age Factors; D000818:Animals; D048788:Growth and Development / Q000502:physiology*; D006801:Humans; D008239:Lysine / Q000378:metabolism*; D009751:Nutritional Requirements; D014176:Protein Biosynthesis / Q000502:physiology*
D008239:Lysine