Plasma amino acid profiles in preterm infants receiving Vamin 9 glucose or Vamin infant.

Amino acid profiles were measured in 29 low-birth-weight infants receiving either Vamin 9 glucose (n = 18, group A) or Vamin Infant (n = 11, group B) as the amino acid source in parenteral nutrition; intake was otherwise identical. Infants were sampled when receiving 430 mgN/kg per day (3.2 g/kg per day amino acids) and 90 non-protein kcal/kg per day. There was no difference between groups in birth weight, gestational or postnatal age. The percentage N retention was similar in both (68 and 60%, groups A and B respectively). Phenylalanine and tyrosine levels were higher in those who received Vamin 9 glucose but 55% of infants given Vamin Infant had tyrosine levels below the lower limit of the target range. Cysteine levels were low in both groups. Further modification of the amino acid composition of parenteral solutions for the newborn is necessary. If sufficient non-protein energy can be provided the risk of abnormally high amino acid levels is reduced.