Estimation of daily fluoride intake of infants using the microdiffusion method

Area of Science:

• Pediatric Nutrition
• Dental Public Health
• Environmental Health

Background:

• The standard for daily fluoride intake (DFI) in Japan has primarily focused on adults since the 1950s.
• Recent dietary changes necessitate a review of DFI, especially for infants with higher fluoride bioavailability.
• Limited research exists on infant DFI, despite potential risks of excess intake.

Purpose of the Study:

• To investigate the daily fluoride intake (DFI) in Japanese infants.
• To inform adequate fluoride application strategies for this age group.
• To address the lack of recent DFI data in Japan.

Main Methods:

• Analyzed fluoride concentrations in 20 infant foods, 5 infant formulas, and 5 bottled waters.
• Utilized microdiffusion and fluoride ion-selective electrode methods for accurate measurement.
• Calculated DFI for infants at 5, 7, 9, and 12 months of age.

Main Results:

• The estimated DFI for Japanese infants aged 5, 7, 9, and 12 months was 185.34 μg/day, 181.16 μg/day, 174.59 μg/day, and 179.19 μg/day, respectively.
• These intake levels appear lower than established standards in other countries.

Conclusions:

• DFI from infant foods and beverages in Japan is estimated to be below international benchmarks.
• Country-specific lifestyles and dietary patterns necessitate a new DFI standard for Japanese children.
• A revised guideline is crucial for ensuring adequate fluoride recommendations for infants in Japan.