Urinary Fluoride Excretion among Children in Qatar - Abstract
Aim: The aim of this study was to assess the daily urinary fluoride excretion of children in Qatar.
Methods: The sampling frame was children who participated in the Qatar Child Oral Health Survey 2017 (QCOHS 2017). A sub-group of QCOHS 2017 were invited to
participate in the study which was conducted in early 2019. Some 223 children in 25 schools in Doha, Al Khor and Al Rayyan were recruited. All were in areas served by the
desalinated, low fluoride water supply. The child’s age, sex, height (cm) and weight (kg) were collected and time of day of the collection, brushing their teeth with toothpaste and/
or having breakfast that morning noted. The concentration of fluoride was determined using a specific fluoride ion electrode, after adding TISAB III in a 10:1 (v/v) ratio. Urinary
creatinine concentration was measured by the enzymic creatinine assay based on colorimetric method for hydrogen peroxide measurement.
Results: The mean fluoride concentration was 0.36 mgF/L, the F:Cr ratio was 0.41 mgF:gCr/L, the fluoride excretion per day was 0.19 mg/day and 0.0061 mg/kgbw/day.
Fluoride excretion was similar across all ages, sexes and for Qatari and non-Qatari children.
Children who ate breakfast and who brushed their teeth on the morning before the collection of the sample had significantly higher fluoride excretion. On the basis that between
1/3rd and 1/2th the fluoride intake is excreted, fluoride intake in the children would be between 0.38 to 0.57 mgF/day and 0.012 to 0.018 mgF/kgbw/day. The range of 0.05-
0.07 mgF/kgbw/day has been suggested as a lower and upper bound of optimal fluoride intake.
Conclusion: The level of fluoride excretion leaves considerable scope to consider increasing children’s exposure to fluoride for the prevention of caries.