In a preterm infant, which amino acid is separately added to parenteral nutrition solutions due to solubility concerns?

In a preterm infant, which amino acid is separately added to parenteral nutrition solutions due to solubility concerns?

• A. Glycine
• B. Cysteine
• C. Methionine
• D. Phenylalanine

Answer: (B)

In neonatal parenteral nutrition, certain amino acids are added separately because they affect the stability and solubility of the overall solution, as well as meet specific nutritional needs of preterm infants. Cysteine is the one that’s commonly added separately because it is poorly soluble in standard PN mixtures and can help keep minerals like calcium and phosphate in solution. Preterm infants have a limited ability to synthesize cysteine, so they rely on an exogenous supply. Providing cysteine, often as L-cysteine or L-cysteine hydrochloride, serves a dual purpose: it supplies a conditionally essential amino acid and lowers the solution’s pH, which improves the solubility of calcium and phosphate and prevents precipitation. This helps deliver adequate minerals safely in the PN. So, cysteine is added separately to address both the infant’s cysteine needs and the chemical solubility/stability concerns inherent to neonatal PN.

In neonatal parenteral nutrition, certain amino acids are added separately because they affect the stability and solubility of the overall solution, as well as meet specific nutritional needs of preterm infants. Cysteine is the one that’s commonly added separately because it is poorly soluble in standard PN mixtures and can help keep minerals like calcium and phosphate in solution.

Preterm infants have a limited ability to synthesize cysteine, so they rely on an exogenous supply. Providing cysteine, often as L-cysteine or L-cysteine hydrochloride, serves a dual purpose: it supplies a conditionally essential amino acid and lowers the solution’s pH, which improves the solubility of calcium and phosphate and prevents precipitation. This helps deliver adequate minerals safely in the PN.

So, cysteine is added separately to address both the infant’s cysteine needs and the chemical solubility/stability concerns inherent to neonatal PN.