Pediatric Nephrology

, Volume 24, Issue 1, pp 61–66

Urinary vitamin A excretion in very low birth weight infants

  • Britta Nagl
  • Andrea Loui
  • Jens Raila
  • Ursula Felderhoff-Mueser
  • Michael Obladen
  • Florian J. Schweigert
Original Article

DOI: 10.1007/s00467-008-0965-0

Cite this article as:
Nagl, B., Loui, A., Raila, J. et al. Pediatr Nephrol (2009) 24: 61. doi:10.1007/s00467-008-0965-0

Abstract

Vitamin A (VA) deficiency in very low birth weight (VLBW) infants is associated with an increased risk for disorders related to kidney and lung maturation and function. VA losses through increased urinary retinol (ROH) excretion might contribute to this deficiency risk. The mechanism accounting for ROH loss in the urine has not yet been clarified. The aim of this study was to assess the excretion of ROH, retinol-binding protein 4 (RBP4) and transthyretin (TTR) in urine from VLBW infants in comparison with that in term infants in relation to kidney function. Urine specimens were collected from 15 VLBW infants (birth weight < 1,500 g) as well as from 20 term infants during the first 2 days after birth. ROH in urine was detectable in 14 of the 15 VLBW infants at a median concentration of 234 nmol/g creatinine. In the group of term infants, 17 of the 20 excreted ROH, but at an approximately five-times lower concentration (P < 0.001). Excretion of RBP4 and TTR was also much higher in VLBW infants (both P< 0.001). The urinary ROH excretion in VLBW infants may be related to the impaired tubular handling of its carrier proteins RBP4 and TTR. Thus, ROH excretion might contribute to an increased risk of VA deficiency, especially in VLBW infants.

Keywords

Vitamin AUrinary retinolUrinary RBP4Very low birth weight infantsKidney functionUrine

Copyright information

© IPNA 2008

Authors and Affiliations

  • Britta Nagl
    • 1
    • 3
  • Andrea Loui
    • 2
  • Jens Raila
    • 1
  • Ursula Felderhoff-Mueser
    • 2
  • Michael Obladen
    • 2
  • Florian J. Schweigert
    • 1
  1. 1.Department of Physiology and Pathophysiology, Institute of Nutritional ScienceUniversity of PotsdamPotsdamGermany
  2. 2.Department of Neonatology, Virchow HospitalCharité, University Medicine BerlinBerlinGermany
  3. 3.Institute of Nutritional ScienceUniversity of PotsdamNuthetalGermany