This paper compares measurements of the average amount of thyroid hormones (T3, T4, and TSH) in people with thyroid disease (specifically, hypothyroidism) and people without thyroid disease, with respect to fluoride concentrations in two levels 0–0.29 and 0.3–0.5 (mg/L) in drinking water and several other variables (gender, family history, water consumption, exercise, other disease conditions). This evidence concerns the gene TG and thyroid gland disorder.