title: Excretion of vitamin A in urine of women during normal pregnancy and pregnancy complications.
abstract: OBJECTIVE
  The renal function, including the excretion of low-molecular-weight proteins, changes during pregnancy and may cause a urinary excretion of retinol-binding protein (RBP). Whether it is accompanied by a substantial loss of vitamin A (retinol) has not been established yet. We therefore determined the excretion of retinol and RBP in urine of pregnant women.
  
  
  METHODS
  The study involved analyses of urine samples from 40 healthy pregnant women and 29 women with pregnancy complications during the third trimester. Analyses of plasma and urine of 7 healthy women and 5 women with pregnancy complications were also carried out 6 weeks antepartum, at time of delivery and 1 week postpartum.
  
  
  RESULTS
  Urinary retinol was higher in women who suffered from pregnancy disorders with an influence on maternal metabolism (p < 0.01). RBP was excreted at substantial concentrations in the urine of all 69 women, but there were no differences between the groups. Women with a concomitant excretion of retinol had higher levels of urinary RBP than those without a retinol excretion (p < 0.05). Differences in plasma retinol and RBP were not significant.
  
  
  CONCLUSIONS
  The excretion of urinary retinol may increase significantly during pregnancy complications, which needs further clarification to which extent this condition may negatively affect the vitamin A status in such women.
authors.affiliation: Institute of Nutritional Science, University of Potsdam, Nuthetal (Bergholz-Rehbrücke), Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Raila
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wirth
authors.forename: Frank
authors.initials: F
authors.lastname: Chen
authors.forename: Ulrich
authors.initials: U
authors.lastname: Buscher
authors.forename: Joachim W
authors.initials: JW
authors.lastname: Dudenhausen
authors.forename: Florian J
authors.initials: FJ
authors.lastname: Schweigert
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D049590:Postpartum Period / Q000097:blood / Q000652:urine; D011247:Pregnancy / Q000652:urine*; D011248:Pregnancy Complications / Q000097:blood / Q000652:urine*; D011263:Pregnancy Trimester, Third / Q000097:blood / Q000652:urine; D012177:Retinol-Binding Proteins / Q000378:metabolism / Q000652:urine*; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A / Q000097:blood / Q000652:urine*
chemical_list: D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A