title: Excess iodinuria in infants and its relation to the iodine in maternal milk.
abstract: OBJECTIVE
  Iodine is an essential micro nutrient, and a deficiency or excessive intake of this mineral is related to changes in thyroid function. In Brazil, both deficiency and excessive intake of iodine are common; however, excessive intakes have recently been observed. Thus, the objective of the present study was to assess the iodine concentration in maternal milk, taking into account the salt iodine concentration of the participating households and in the infants' urine.
  
  
  METHODS
  Urine samples from 33 infants (less than 6 months of age), maternal milk samples and samples of the kitchen salt used by the mothers were collected. The iodine levels in the urine and maternal milk were assessed by ICP-MS; the iodine levels in the salt were assessed by titration.
  
  
  RESULTS
  The median iodinuria value in the infants was 293 μg/L; the mean iodine concentration was 206 μg/L in the maternal milk and 39.9 mg I/kg in the salt. There was a positive correlation between the iodine concentration in the maternal milk and the infant iodinuria value.
  
  
  CONCLUSIONS
  The median infant iodinuria was elevated due to the high iodine concentration present in the maternal milk. High iodine values were caused by high salt iodine levels, which should be reduced.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, Avenida Bandeirantes 3900, Monte Alegre, 14049-900 Ribeirão Preto, SP, Brazil. livia.lima@usp.br
authors.forename: Livia Fernandes
authors.initials: LF
authors.lastname: de Lima
authors.forename: Fernando
authors.initials: F
authors.lastname: Barbosa
authors.forename: Anderson Marliere
authors.initials: AM
authors.lastname: Navarro
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007455:Iodine / Q000032:analysis* / Q000652:urine*; D013058:Mass Spectrometry; D008895:Milk, Human / Q000737:chemistry*
chemical_list: D007455:Iodine