Serum copper and zinc levels in the preterm infant. A longitudinal study of the first year of life.

Serial determinations were carried out on 27 male and 21 female preterm infants (gestational age 28-36 weeks) throughout the first year of life. Serum copper at birth was 0.33 +/- 0.20 micrograms/ml (n equal 8); at 9 weeks, 0.77 +/- 0.19 micrograms/ml (n = 22); at 24 weeks, 1.00 +/- 0.27 micrograms/ml (n = 31), and at 52 weeks 1.21 +/- 0.27 micrograms/ml (n = 40). Serum zinc at birth was 1.03 +/- 0.16 micrograms/ml (n = 9); at 9 weeks, 0.71 +/- 0.11 micrograms/ml (n = 17); at 24 weeks, 1.02 +/- 0.20 micrograms/ml (n = 20), and at 52 weeks, 1.19 +/- 0.34 micrograms/ml (n = 33). The results of this study compare well with values previously reported for infants studied at selected age points.