Fluoride and Osteoporosis

All substances are poisons; there is none that is not a poison. The right dose distinguishes a poison and a remedy.

Paracelsus

Paracelsus could have been talking about fluoride. At high doses, it can be lethal. At low doses (1 to 2 mg/d), it prevents dental caries. At intermediate doses (8 to 80 mg/d, which might be encountered in geographic regions with high fluoride levels in well water or in settings of industrial exposure to cryolite dust), skeletal fluorosis develops. Taking advantage of this osteosclerosing effect, which is toxic in a different setting, clinical investigators have used fluoride to increase bone mass in patients with osteoporosis for the past 30 or more years. Although it is now an approved treatment in several European countries, it may remain an investigational drug in the United States, mainly because, as a nonpatentable inexpensive agent, it has no commercial patron.

Recognizing that problem, the National Institutes of Health (NIH), in 1980, launched a two-center, 48-month trial of fluoride efficacy and safety. Only one center recruited enough participants to produce analyzable results and when the outcomes were reported [1], they were construed as negative. Fluoride, although it dramatically increased bone mass, failed to decrease spine fracture frequency and possibly increased the risk for extremity fractures [1]. The preparation used also produced gastric irritation, bleeding, and …