Zinc deficiency limiting head growth to discharge in extremely low gestational age infants with insufficient linear growth: a cohort study

To assess the relationship of size for age with zinc deficiency in extremely low gestational age (GA) infants (23–28 weeks, ELGANs) who had insufficient linear growth despite optimizing other nutrients and to analyze changes in fronto-occipital circumference (FOC), weight and length with zinc supplementation. Retrospective cohort study. Among 302 ELGANs, a serum zinc concentration was obtained in 52 with insufficient linear growth (17%). Zinc deficiency (serum concentration 2 weeks improved FOC growth to discharge or 50 weeks postmenstrual age in infants with Zn deficiency. However, neither linear growth nor weight gain improved with Zn supplementation. Zinc deficiency was diagnosed in 14% ELGANs in this cohort. Zinc supplementation for >2 weeks improved FOC growth but not linear growth or weight gain.