title: Impact of aging on urinary excretion of iron and zinc.
abstract: METHODS
  Data about the influence of aging on urinary excretion of iron and zinc are scarce. The objective of the present study was to compare the concentration of zinc and iron in the urine of healthy elderly subjects and younger adults.
  
  
  METHODS
  Seven healthy elderly subjects and seven younger adults were selected and submitted to biochemical, clinical, and nutritional tests. After a fasting period, 12-hour urine was collected for the determination of iron and zinc concentrations by graphite furnace atomic absorption spectrophotometry.
  
  
  RESULTS
  Urinary zinc and iron concentrations of the elderly subjects were not significantly different from that of younger adults. However, the total zinc and iron urinary clearance in 24 hours for the elderly was significantly higher compared with that of younger adults.
  
  
  CONCLUSIONS
  There is an increase in urinary iron and zinc clearance with aging. The values reported in this manuscript may be used as references in future studies.
authors.affiliation: Division of General Internal and Geriatric Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil. ; Division of Clinical Nutrition, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Karina
authors.initials: K
authors.lastname: Pfrimer
authors.affiliation: Division of Clinical Nutrition, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Rutinéia Fátima
authors.initials: RF
authors.lastname: Micheletto
authors.affiliation: Division of Clinical Nutrition, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Julio Sergio
authors.initials: JS
authors.lastname: Marchini
authors.affiliation: Division of Clinical Nutrition, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Gilberto João
authors.initials: GJ
authors.lastname: Padovan
authors.affiliation: Division of General Internal and Geriatric Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Julio Cesar
authors.initials: JC
authors.lastname: Moriguti
authors.affiliation: Division of General Internal and Geriatric Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ferriolli
keywords: atomic absorption spectrophotometry; iron; micronutrients; physiology of aging; zinc