title: Critical evaluation of previously published data on the fractional urinary fluoride excretion in young children.
abstract: BACKGROUND
  There have been several investigations comparing total fluoride intake and the urinary fluoride excretion in young children. Average results of the fractional urinary fluoride excretion (FUFE) reported for this age group are controversial.
  
  
  OBJECTIVE
  To analyse previously published results exploring the influence that some metabolic variables, such as the F-dose (mg F/kg body weight), rate of urinary fluoride excretion, age and body weight, might have on FUFE values.
  
  
  METHODS
  Previously published results on average FUFE values in young children were analysed by means of bivariate correlations and when available, individual FUFE values were studied using multiple linear regression models.
  
  
  RESULTS
  Published average FUFE values for young children are linearly correlated with the inverse of daily F-dose (r = 0.90; p < 0.0005). Individual FUFE values can be predicted by means of a multiple regression model using (dose)(-1), rate of F urinary excretion and age as significant predictors; multiple R2 = 0.947, and p < 0.0001, for all of the partial regression coefficients.
  
  
  CONCLUSIONS
  Young children appear not to have a single average value for FUFE. A high proportion of its variability (81%) is explained by the inverse of the F-dose. About 95% of the variability of individual FUFE values for this age group is explained by (dose)(-1), rate of urinary F-excretion and age.
authors.affiliation: Institute of Nutrition and Food Technology, University of Chile, Santiago. avilla@inta.cl
authors.forename: Alberto E
authors.initials: AE
authors.lastname: Villa
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D001835:Body Weight; D002327:Cariostatic Agents / Q000008:administration & dosage / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005459:Fluorides / Q000008:administration & dosage / Q000378:metabolism / Q000652:urine*; D006801:Humans; D016014:Linear Models; D008657:Metabolic Clearance Rate
chemical_list: D002327:Cariostatic Agents; D005459:Fluorides