Aminoacid infusion induced depression of serum folate after cholecystectomy.

Aminoacid solutions were given to cholecystectomy patients for a period of 48 h starting 24 h after the operation. Infusion of the aminoacid component of parenteral nutrition regimens, without calorie source, frequently led to an acute fall in the serum folate concentration. The degree of depression varied with different commercial aminoacid solutions. (Aminoplex 14 = c. 60%, Vamin = 30%, Aminosol = c. 0%). The folate depression by Vamin infusion was unaffected by supplementation with L-methione but was alleviated by the addition of glycine. As a consequence of surgical operation itself, folate values fell by 37% during the 24 h following cholecystectomy. This seems likely to increase the risk of haematological toxicity (i.e. acute leukopenia and thrombocytopenia) in patients given folate-free parenteral nutrition after a surgical operation.