Fluoride intake of infants in New Zealand.

Since the fluoride (F-) intake of New Zealand infants and young children is not known, a study was designed to determine and compare the F- intake of infants, aged 11 to 13 months, residing in fluoridated (F) and non-fluoridated (NF) areas. Parents of 60 infants duplicated quantitatively and qualitatively all food and drink that the infants ingested during a three-day period. The acid-diffusible F- content in the liquid homogenate was isolated by the HMDS-HCl diffusion technique (Taves, 1968) and measured by a fluoride electrode. The ionic F- in samples of breast milk was measured directly by the electrode. In the F area, the F- content of the food and drinks of 31 subjects ranged from 0.130 to 0.679 mg/kg (mean, 0.320; SD, 0.168); in the NF areas, the F- content of the food and drinks of 29 subjects ranged from 0.036 to 0.281 mg/kg (mean, 0.095; SD, 0.053). The dietary intake ranged from 0.089 to 0.549 mg F/day (0.009-0.056 mg F/kg bw) in the F area, and from 0.038 to 0.314 mg F/day (0.004-0.038 mg F/kg bw) in the NF area. Including F- from tablets and toothpastes, total intake ranged from 0.093 to 1.299 mg F/day (0.009-0.150 mg F/kg bw) and from 0.039 to 0.720 mg F/day (0.004-0.061 mg F/kg bw) in F and NF areas, respectively. The mean dietary intake of infants in the F area was about half the recommended "optimal" range; in the NF areas, the dietary intake was five to seven times less than the optimal.(ABSTRACT TRUNCATED AT 250 WORDS)