Among infants supplemented with carnitine , there was no evidence of effect on weight gain , lipid utilization or ketogenesis .
REVIEW ER 'S CONCLUSIONS We found no evidence to support the routine supplementation of parenterally fed neonates with carnitine
BACKGROUND Carnitine , a quaternary amino acid , plays an important role in the oxidation of long chain fatty acids .
Both breast milk and infant formulas contain carnitine .
However , it is not routinely provided in parenteral nutrition solutions .
Non supplemented parenterally fed infants have very low tissue carnitine levels .
The clinical significance of this is uncertain .
Carnitine deficiency may be an etiological factor in the limited ability of premature babies to utilize parenteral lipid .
In vitro studies have suggested that fatty acid oxidation is impaired when the tissue carnitine levels fall below 10 % of normal .
Therefore relative carnitine deficiency may impair fatty acid oxidation , thus reducing the available energy and impairing growth .
OBJECTIVES The primary aim of this review is to determine whether carnitine supplementation of parenterally fed neonates will improve weight gain .
The secondary aims are to determine the effect on lipid tolerance and ketogenesis .
Effects of high carnitine supplementation on substrate utilization in low-birth-weight infants receiving total parenteral nutrition.
Parenterally fed preterm neonates are known to be at risk for carnitine deficiency . We studied substrate utilization in low-birth-weight infants receiving total parenteral nutrition ( TPN ) with ( A ) and without ( B ) supplementation of 48 mg carnitine.kg-1.d-1 on days 4 - 7 ( birth weights 1334 + /- 282 vs 1318 + /- 248 g , gestational age 32 + /- 2 vs 32 + /- 2 wk , A vs B , respectively ) . TPN consisted of 11 g glucose.kg-1.d-1 and 2.4 g.kg-1.d-1 of both protein and fat . Plasma carnitine concentrations at day 7 were for free carnitine 11.8 + /- 5.0 vs 164 + /- 56 mumol/L and for acyl carnitine 3.8 + /- 2.0 vs 33.9 + /- 15.4 mumol/L , respectively . Indirect calorimetry at day 7 showed a higher fat oxidation ( 0.21 , -0.31 to + 0.60 vs 1.18 , 0.70 to 1.95 g. kg-1.d-1 , respectively , P less than 0.02 , median and interquartile range ) in group B and a higher protein oxidation ( 0.37 , 0.30 - 0.43 vs 0.63 , 0.53 - 0.88 g.kg-1.d-1 , P less than 0.001 ) . The time to regain birth weight was also higher in group B ( 7 , 5.5 - 9 vs 9 , 7 - 14 d , P less than 0.05 ) . Carnitine supplementation and calorie intake were the best explanatory variables for metabolic rate ( R2 = 0.45 , P less than 0.002 ) . We conclude that carnitine supplementation of TPN in this dosage does not seem advisable
Among infants supplemented with carnitine , there was no evidence of effect on weight gain , lipid utilization or ketogenesis .
REVIEW ER 'S CONCLUSIONS We found no evidence to support the routine supplementation of parenterally fed neonates with carnitine
BACKGROUND Carnitine , a quaternary amino acid , plays an important role in the oxidation of long chain fatty acids .
Both breast milk and infant formulas contain carnitine .
However , it is not routinely provided in parenteral nutrition solutions .
Non supplemented parenterally fed infants have very low tissue carnitine levels .
The clinical significance of this is uncertain .
Carnitine deficiency may be an etiological factor in the limited ability of premature babies to utilize parenteral lipid .
In vitro studies have suggested that fatty acid oxidation is impaired when the tissue carnitine levels fall below 10 % of normal .
Therefore relative carnitine deficiency may impair fatty acid oxidation , thus reducing the available energy and impairing growth .
OBJECTIVES The primary aim of this review is to determine whether carnitine supplementation of parenterally fed neonates will improve weight gain .
The secondary aims are to determine the effect on lipid tolerance and ketogenesis .