The relationship of bone mass and fracture history to fluoride and calcium intake: a study of three communities.

Stimulated by the suggestion that water fluoride greater than 1 mg/L may protect against osteoporosis, we studied bone mass of women in three rural communities with differing mineral content of the water supply. Mean fluoride and calcium of community drinking waters were 4 mg/L and 16 mg/L, respectively, high fluoride community; 1 mg/L and 375 mg/L, respectively, high calcium community; and 1 mg/L and 65 mg/L, respectively, low calcium community. Bone mass was measured by single photon absorptiometry, and women were interviewed about fracture history, dietary intake, and other important covariates. We observed no protective effect with higher fluoride intake. Bone mass was lower in older women from the high fluoride community though not statistically so; these women reported significantly more fractures. There was no observed community difference in young women's bone mass or fracture history. Young women in the high fluoride community consuming calcium and vitamin D in excess of 800 mg/day and 400 IU/day, respectively, had significantly better bone mass (p less than 0.05) than their peers.