Effect of Intravenous L‐Carnitine on Growth Parameters and Fat Metabolism during Parenteral Nutrition in Neonates

To determine whether intravenous carnitine can improve nutritional indices, neonates requiring parenteral nutrition were randomized into carnitine treatment (n = 23) and control (n = 20) groups. Observed plasma lipid indices, carnitine and nitrogen balances, and plasma carnitine concentrations were not different in the prestudy period. Under standardized, steady‐state conditions, 0.5 g/kg Intralipid was administered intravenously over 2 hr prior to carnitine administration, after infants received 7 days of 50 μmol/kg/day, and after a second 7 days of 100 μmol/kg/day of continuous intravenous L‐carnitine as part of parenteral nutrition. Triglyceride (TGY), free fatty acid (FFA), acetoacetate (AA), β‐hydroxybutyrate (BOB), and plasma carnitine concentrations were measured prior to and at 2, 4, and 6 hr after the initiation of the lipid bolus. Twenty‐four‐hour urine collections for nitrogen and carnitine balance were obtained on days 7 and 14. Neonates receiving carnitine had significantly greater concentrations of plasma carnitine on days 7 and 14 ( p < 0.001). Greater nitrogen ( p < 0.05) and carnitine ( p < 0.001) balances and weight gain (week 2, p < 0.05) were found in the carnitine‐supplemented group when compared with controls. On day 14, (BOB + AA)/ FFA ratios were significantly higher ( p < 0.05), and peak TGY concentrations and 6‐hr FFA concentrations were significantly lower ( p < 0.05) in the treatment group. Carnitine supplementation was associated with modest increases in growth and nitrogen accretion possibly by enhancing the neonate's ability to utilize exogenous fat for energy. (Journal of Parenteral and Enteral Nutrition 14 :448–453, 1990)