Effects of fluoride on thyroid hormone biosynthesis. Studies in a highly sensitive test system

Area of Science:

• Endocrinology
• Toxicology
• Public Health

Background:

• Fluoride supplementation is recommended for preventing dental caries.
• Concerns exist regarding potential adverse effects of fluoride on thyroid function.
• Understanding fluoride's impact on the thyroid is crucial for public health recommendations.

Purpose of the Study:

• To evaluate the potential antithyroid properties of fluoride.
• To assess the effects of fluoride on thyroid hormone biosynthesis in a rat model.

Main Methods:

• Rats were administered varying concentrations of fluoride in drinking water.
• Serum fluoride levels were measured to confirm exposure.
• Thyroid function markers, including iodine organification and hormone synthesis, were analyzed.

Main Results:

• Elevated serum fluoride concentrations were achieved.
• No antithyroid effects were observed, even at high fluoride doses near toxic levels.
• Key steps in thyroid hormone biosynthesis and thyroglobulin iodination remained unaffected.

Conclusions:

• Fluoride supplementation, as recommended for dental caries prevention, does not appear to possess antithyroid properties.
• The thyroid gland's ability to synthesize hormones is not compromised by fluoride exposure within the studied range.