Carnitine supplementation of parenterally fed neonates.

This was a systematic review of randomized trials in newborns requiring parenteral nutrition, including premature infants, very low birth weight infants, and some term post-surgical neonates. Across the carnitine arms, 108 participants were randomized in total, with individual carnitine-arm sample sizes ranging from 6 to 41.

Carnitine supplementation was given as the active intervention in 8 randomized trials of parenterally fed neonates, with routes and regimens varying by study. Doses ranged from 50 to 150 micromol/kg/day, given intravenously, added to lipid emulsion, or given enterally/orally, for about 7 days to until enteral feeds were established or 40 weeks' gestation.

Carnitine supplementation did not show convincing benefit for weight gain, lipid tolerance, or ketogenesis in neonates receiving parenteral nutrition. Weight gain results were inconsistent across small trials, with examples including MD 5.60 [-0.12, 11.32] in Bonner 1995b, MD -5.53 [-34.91, 23.85] in Coran 1985, and pooled neutral findings for later outcomes such as MD 0.80 [-3.35, 4.95] at 2 to 4 weeks in Shortland 1998. Secondary outcomes were also largely null: free fatty acids pooled at -0.16 [-0.37, 0.05], triglycerides at -0.69 [-1.84, 0.45], and maximum lipid tolerated at 0.09 [-0.20, 0.38]. The review concluded that routine parenteral carnitine supplementation is not justified on the basis of the available randomized evidence.

The evidence base was small, short term, and methodologically diverse, with varied doses, routes, and outcome timing across studies. Several trials were underpowered and some outcomes were incompletely reported, limiting confidence in pooled estimates and reducing generalizability to neonates needing long-term total parenteral nutrition.