Serum zinc and copper levels in infants admitted to the neonatal intensive care unit
Related Experiment Video
Updated: Aug 15, 2025
Atomic Absorbance Spectroscopy to Measure Intracellular Zinc Pools in Mammalian Cells
Published on: May 16, 2019
Kei Ogasawara1, Yoshinobu Honda2, Hayato Go3
1Department of Premature and Neonatal Medicine, Iwaki City Medical Center, Fukushima, Japan; Department of Pediatrics, Fukushima Medical University, Fukushima, Japan.
Insights
Infants in the neonatal intensive care unit (NICU) often show declining serum zinc levels, especially premature infants. Small-for-gestational-age (SGA) infants had higher serum copper levels upon admission.
Area of Science:
- Neonatal Medicine
- Trace Element Metabolism
- Pediatric Nutrition
Background:
- Reference values for serum zinc and copper in neonates and infants are not well-established.
- Trace elements are vital for infant development and health.
Purpose of the Study:
- To determine the trend of serum zinc levels in infants admitted to the neonatal intensive care unit (NICU).
- To compare serum zinc and copper levels at admission between small-for-gestational-age (SGA) and non-SGA infants.
Main Methods:
- Retrospective study of 339 infants admitted to the NICU.
- Serum zinc and copper levels measured on admission.
- Serum zinc monitored monthly until discharge.
Main Results:
- Serum zinc decreased significantly in infants born before 30 weeks gestation.
- Infants born at or before 34 weeks gestation showed zinc deficiency by 2 months of age.
- A negative correlation was observed between gestational age and serum zinc levels, and between serum zinc and serum copper levels.
- Small-for-gestational-age (SGA) infants had significantly higher serum copper levels at admission.
Conclusions:
- Infants born at or before 34 weeks gestation require enteral zinc supplementation by 2 months of age.
- Higher serum copper in SGA infants warrants further investigation into its developmental impact.
Objectives:
Zinc and copper are trace elements, but their reference values during the neonatal and infant periods are not clear. We aimed to determine the trend of serum zinc levels in infants admitted to the neonatal intensive care unit and compare serum zinc and serum copper levels at admission between small-for-gestational-age (SGA) and non-SGA infants.
Methods:
From 406 patients admitted to the neonatal intensive care unit from January 2009 to September 2012, 339 patients were included in this retrospective study. Blood samples were collected on admission, and serum zinc and serum copper levels were measured. Serum zinc was tested every month until discharge.
Results:
Serum zinc levels of infants born at <30 wk of gestation decreased by 46% in the first month of life. All infants born at ≤34 wk of age became zinc deficient at 2 mo of age. The relationship between gestational age and serum zinc level at admission had a negative correlation (Spearman's rank correlation cofficients) = -0.66; P < 0.001). There was a negative correlation between serum zinc and serum copper at admission (rs = -0.49; P < 0.001). Serum copper levels of SGA infants at admission were significantly higher than those of non-SGA infants (P < 0.001).
Conclusions:
All of the infants admitted to the neonatal intensive care unit at ≤34 wk of gestation were zinc deficient by 2 mo of age, suggesting the need for enteral zinc administration. Serum copper was higher in SGA infants than in non-SGA infants on admission, but further studies are needed to determine whether excess copper affects development.
