Urinary zinc excretion in infancy
Sievers, E.; Oldigs, H.D.; Dörner, K.; Schaub, J.
Journal of Trace Elements and Electrolytes in Health and Disease 4(1): 31-35
1990
ISSN/ISBN: 0931-2838 PMID: 2135955 Document Number: 352380
In view of the conflicting data on urinary Zn excretion in infancy the possible influence of contamination, collecting methods, nutrition (human milk versus formula) and longitudinal changes during the first 16 weeks of life were investigated in 25 infants. Methodical investigation showed the importance of avoiding contamination from Zn-containing creams applied to the genital region. Mid-stream urine samples reduce the possibility of contamination. Increased urinary Zn concentration was found in pre-term infants under theophylline or caffeine medication. The median daily urinary Zn excretion in healthy breast-fed term infants declined significantly from 0.063 (range, 0.027-0.111) mg/kg body weight at 2 weeks of age to 0.018 (0.004-0.059) mg/kg at 16 weeks. Corresponding values for formula-fed term infants were 0.029 (0.025-0.0630) and 0.025 (0.007-0.059) mg/kg.