Fluoride Action Network


No significant differences in protein-bound iodine levels and thyroid gland abnormalities were found when two population groups, one group of 106 persons who used water that naturally contained fluorides (3.48 ppm)  and one control group of 109 persons who used essentially fluoride-free water, were compared. All subjects has been residents of their respective communities for more than ten years. There were no indications that prolonged ingestion of fluoride affects thyroid gland size or function at the levels studied.

*Study available at https://jada.ada.org/article/S0002-8177(64)92014-8/pdf