ليزين

Lysine is an essential amino acid that is not produced in the body and must be ingested in the diet. It is found in large quantities in legumes, cereals, red meat, sea fish, cheese and eggs. It is necessary for the synthesis of proteins in the body and multiple metabolic functions. It is used as a dietary supplement without indications supported by scientific evidence.

It is excreted in breast milk in a clinically insignificant amount (0.5% of the administered dose) and in the form of proteins. ^{(Irving 1988, Thomas 1991)}

It is naturally contained in breast milk and its concentration, which is highest in colostrum, decreases during the first month of breastfeeding. ^{(Harzer 1984, Janas 1986, Spevacek 2015)}

The concentration of lysine, other amino acids and proteins is higher in the milk of mothers of preterm infants than in the milk of mothers of term infants. ^{(Atkinson 1980)}

Maternal dietary protein and amino acid intake is not associated with the amino acid composition of human milk in an accommodated environment. ^{(Juncker 2024)}

Pasteurisation slightly decreases the concentration of lysine and other amino acids (Silvestre 2006, Valentine 2010), although it increases the amount of bioavailable lysine. ^{(Baro 2011)}

It is considered safe for use during breastfeeding. ^{(Amir 2011, The Royal Women's Hospital Fact Sheet 2013)}

Daily lysine requirements are estimated at around 30 mg/kg in adults and double that in children under one year of age ^{(FEN 2013)}. A maximum daily amount of 2,250 mg of L-lysine is acceptable from a safety point of view for use as a food supplement. ^{(AESAN 2012)}