Associations of fluoride intake with children’s bone measures at age 11

Abstract

Background Relationships between fluoride intake and bone health continue to be of interest, as previous studies show conflicting results. Objectives The purpose is to report associations of fluoride intake with bone measures at age 11. Methods Subjects have been participating in the ongoing Iowa Fluoride Study/Iowa Bone Development Study. Mothers were recruited postpartum during 1992–95 from eight Iowa hospitals, and detailed fluoride questionnaires were sent every 1.5–6 months. From these, combined fluoride intakes from water sources (home, childcare, filtered, bottled), other beverages, selected foods, dietary fluoride supplements, and dentifrice were estimated at individual points and cumulatively (with area-under-the-curve). Subjects received dual-energy x-ray absorptiometry (DXA) scans of proximal femur (hip), lumbar spine and whole body (Hologic QDR 4500A). DXA results (bone mineral content – BMC; bone mineral density – BMD) were related to fluoride intake in bivariate and multivariable analyses. Results The mean fluoride intake estimated by AUC was 0.68 mg (SD=0.27) per day from birth to 11 years. Associations (Spearman) between daily fluoride intake (mg F/d) and DXA bone measures were weak (r= −0.01 to 0.24 for girls and 0.04 to 0.24 for boys). In gender-stratified, and body size- and Tanner Stage-adjusted linear regression analyses, associations between girls' bone outcomes and fluoride intake for girls were almost all negative, associations for boys were all positive, and none were statistically significant using an α = 0.01 criterion. Conclusions Longitudinal fluoride intake at levels of intake typical in the United States is only weakly associated with BMC or BMD in boys and girls at age 11. Additional research is warranted to better understand possible gender- and age-specific effects of fluoride intake on bone development.

Associations of fluoride intake with children's cortical bone mineral and strength measures at age 11

“…Our results are consistent with several ecological studies (i.e., studies that did not assess fluoride intakes at the individual level, but instead compared bone measures among children living in communities with fluoridated versus non‐fluoridated water) which found no significant differences in bone outcomes by fluoridation status . Furthermore, a previous analysis of the IFS/IBDS data showed only modest relationships between DXA scans of hip, spine, and whole body and fluoride intakes at age 11 , with even weaker associations with DXA outcomes at age 15 .…”

“…A recent cohort study of South African adolescents reported a significant positive association of higher water fluoride (3 ppm versus 0.19 ppm) and radius BMD measured with the Norland single energy ( 125 I) photon absorptiometer in the 14‐year to 15‐year age group, but not in those 10–11 years old . Finally, we found no significant relationships between age 11 DXA bone measures of the hip, lumbar spine, and whole body and fluoride intake from birth to 3, 3–6, 6–8.5, 8.5–11 years, and cumulatively to 8.5 and 11 years .…”

“…Intakes for girls per unit body weight during recent years of life (8.5–11 years) showed statistically significant, negative associations with several bone measures. Differences in effects of fluoride intakes on bone measures for girls versus boys were not seen previously in analyses of age 11 or 15 DXA‐determined BMC and BMD of the same cohort . This new finding could be due to the assessment of different bones, radius and tibia versus hip, spine, and whole body, or the use of pQCT in this study, which provided the opportunity to estimate cortical bone strength in vivo, as well as volumetric density .…”

Fluoride intake and cortical and trabecular bone characteristics in adolescents at age 17: A prospective cohort study

“…Most focused on comparing adults living in fluoridated vs nonfluoridated communities. Very few have investigated the effects of fluoride on bone characteristics in children/adolescents …”

Effect of sodium fluoride with and without ginseng on the submandibular gland of adult male albino rat

“…Approximately 50% of the absorbed fluoride remains associated with hard tissues, whereas all of the remainder is excreted in urine [4][5][6]. It distributes evenly throughout intracellular and extracellular spaces.…”