Zinc, copper, selenium and manganese blood levels in preterm infants

Objective: To measure the zinc, copper, selenium and manganese blood levels in a cohort of 68 preterm infants, and to establish any associations with growth and/or dietary intake. Design: Blood samples were collected at an infant's expected date of delivery (term) and 6 months later. Serum zinc, plasma copper and whole blood manganese were analysed by atomic absorption spectrometry, plasma and red cell selenium were determined by mass spectrometry. Growth and dietary intake determinations have been previously published. Setting: Hampshire, England. Results: Mean (SD) birth weight of the infants was 1.47 (0.434) kg and mean gestation was 31.4 13.8 (2.9) weeks. Mean blood levels at term and 6 months were: serum zinc 12.0 (2.6) mu mol/l an (2.5) mu mol/l; plasma copper 10. 1 (2.6) mu mol/l and 19.2 (3.6) mu mol/l; plasma selenium 0.49 (0.15) mu mol/l and 0.72 (0.14) mu mol/l; red blood cell selenium 1.68 (0.40) mu mol/l and 1.33 (0.19) mu mol/l; and blood manganese 320 (189) mu nmol/l and 211 (68) mu mol/l, respectively. There were no significant associations between levels of zinc and copper and dietary intakes of those nutrients at either age (dietary intakes of selenium and manganese were not determined). Only copper levels at term were significantly associated (r=0.31; p=0.05) with a growth parameter (head circumference). Conclusion: These results provide new information about trace element status in this vulnerable population.