Total fluoride intake in children aged 3 to 4 years--a longitudinal study

Several previous studies using food consumption tables or diet records have estimated that children aged 1 to 12 years resident in fluoridated (1 ppm) areas receive, on average, between 0.05 and 0.07 mg fluoride/kg body weight from foods and drinks alone. In this study, the duplicate-diet approach, which is a more accurate method of determining nutrient intake, was used to determine if levels of fluoride intake from foods and drinks are similar to those estimated from food consumption tables or diet records. Duplicate portions of all foods and drinks consumed over 24 hours by 66 children aged 3 to 4 years resident in fluoridated and low-fluoride areas of New Zealand were collected on three separate days over a period of 12 months and analyzed for fluoride. Fluoride intake from the use and ingestion of toothpastes and fluoride supplements was also determined for each child. It was hypothesized that the total amount of fluoride received by children in low-fluoride areas from diet, toothpastes, and fluoride supplements was similar to that received by children in fluoridated areas from diet and toothpastes. The mean fluoride intake from foods and drinks alone in the low-fluoride areas was 0.008 +/- 0.003 mg/kg body weight (0.15 +/- 0.06 mg/day; n = 34) and in the fluoridated areas was 0.019 +/- 0.009 mg/kg body weight (0.36 +/- 0.17 mg/day; n = 32). The mean fluoride intake from foods and drinks and toothpastes in the low-fluoride areas was 0.027 +/- 0.012 mg/kg body weight (0.49 +/- 0.25 mg/day) and in the fluoridated areas was 0.036 +/- 0.015 mg/kg body weight (0.68 +/- 0.27 mg/day). Fluoride intake from diet alone did not exceed 0.04 mg/kg body weight (0.74 mg/day), and fluoride intake from diet and toothpaste did not exceed 0.07 mg/kg body weight (1.31 mg/day). The results suggest that levels of fluoride intake from foods and drinks alone as estimated by the duplicate-diet approach are much lower than previously estimated from food consumption tables or diet records. It was calculated that if all children in the low-fluoride areas were to take currently recommended dosages of fluoride tablets, which have been based on dietary surveys and diet records, then the total fluoride intake of some children in the low-fluoride areas would exceed that of their counterparts in the fluoridated areas. The results suggest that currently recommended dosages of fluoride tablets need to be further reduced if dental fluorosis in children is to be avoided.