Fluoride Action Network


A study on the serum T4, T3, and TSH levels was performed in 27 patients with chronic skeletal fluorosis and the data obtained were compared with those of 20 healthy persons. The results showed that serum T4 in the patients was lower than in the controls and TSH was higher. While serum T3 showed no significant difference. There was no goiter found in the patients. These data indicate that fluorine may reduce serum T4 by interfering [with] the thyroid function. The increase of TSH secretion is the consequence stimulated by a feedback mechanism but no proliferation and enlargement of the thyroid gland resulted since the reactivity of the thyroid to [a] rise [in] serum TSH stimulation is inhibited by the fluorine.