Objective: To obtain some preliminary data on fluoride retention in young children, measure the fluoride content of 24-h urine and spot morning urine samples and determine the fluoride/creatinine (F/Cr) ratio in spot urine samples.
Method: Eight healthy children aged between 12 and 36 months were recruited from a fluoridated community in the North-East of England. A 3-day dietary diary was used to collect dietary information. Samples of milk, food and other drinks consumed by the children were collected and analysed for fluoride content using a Fluoride Ion Selective Electrode (Orion, 9609). The amount of fluoride ingested through toothbrushing was also measured. A 24-h urine sample was collected from each child during 1 day of the 3 day dietary period.
Results: The mean (±sd) age, weight, height and daily energy intake of the 7 children who completed the study satisfactorily, was 32 (±7) months, 15 (±2) kg, 95 (±9) cm, and 1704 (±348) kcal, respectively. The mean fluoride intake from toothpaste ingestion was higher (0.45±0.26 mg/day) than that from the diet (0.37±0.47 mg/day) for all children. The mean ± sd weight of fluoride excreted through urine was 0.33±0.16 mg/day. The fluoride retention was estimated to be 43%. No relationship between total daily fluoride intake and either 24-h urinary fluoride excretion or F/Cr ratio in the spot urine samples were observed for those children.
Conclusion: The results of this study suggest that fluoride retention in children aged 12 to 36 months may be much lower than previous estimates of 70%.