Essential fatty acid deficiency in parenterally fed preterm infants.

To determine the incidence of essential fatty acid (EFA) deficiency during short term fat-free parenteral nutrition, the authors investigated prospectively the EFA status of nine low birthweight (1145 +/- 343 g) preterm (28.2 +/- 1.9 weeks) infants, in whom delivery of dietary fat was delayed postnatally for 2-9 days. Serial determinations of plasma fatty acids showed that during fat-free alimentation, the major EFA, linoleic acid (LA), decreased rapidly (-0.75% total fatty acids per day), accompanied by a rise in endogenously produced non-essential fatty acid, eicosatrienoic acid (Mead acid). Essential fatty acid deficiency was confirmed biochemically by an elevation in the triene-tetraene ratio in six of the infants, only one of whom developed clinical symptoms. Abnormal fatty acid profiles were corrected within a few days of fat delivery by either intravenous or enteral routes. Essential fatty acids and their metabolites are involved in a wide range of physiological functions vital to postnatal growth and development. Depletion of these nutrients can be corrected by providing a minimum of 0.25 g LA/kg per day (equivalent to 0.50 g/kg per day of 20% intralipid or 30-50 mL/kg per day of breast milk).