Fluoride Action Network


Fluoride intake is known to affect mineralization of both teeth and bones. Few studies have comprehensively assessed fluoride intake and related findings to bone measures. Objectives: To relate fluoride intake from birth to age 4 years to bone measures (spine bone mineral content [bmc] and density [bmd], hip bmc and bmd, total body bmc) at age 5. Methods: Subjects and their parents are participants in the Iowa Bone Development Study, part of the Iowa Fluoride Study (IFS). Parents provided detailed questionnaire data 2-5 times per year concerning water sources and intake from water, beverages, selected foods, dentifrice, and supplements. Individuals’ multiple water sources and major beverages were assayed for fluoride. Combined fluoride intake was calculated. Three fluoride measures were constructed: weighted average intake (AUC F) and weighted average intake per kg body weight (AUC F/kg) from 6 months to 4 years of age (n = 310) and fluoride per kg at 36 months (36 mo F/kg) (n = 331). Dual-energy x-ray absorptiometry (DXA) was conducted with the Hologic QDR-2000. Results: Adjusted for body weight, there was little correlation of AUC F with bone measures except for hip bmc (0.14, p<0.025). There were no significant associations between AUC F/kg and gender/weight adjusted bone measures (all p>0.10). Adjusted correlations were stronger for age 36 month F/kg than other single time points: spine bmc (-0.12, p<0.025), spine bmd (-0.12, p<0.05), hip bmc (-0.08, p<0.15), hip bmd (-0.04, p>0.40), and wb bmc (-0.12, p<0.05). Additional research adjusting for calcium intake and physical activity is warranted. Conclusions: Results show the complexity of the relationships between fluoride intake and bone measures.