Effect of Prolonged Administration of Iodine Containing Water Purification Tablets in Man

Tetraglycine hydroperiodide tablets purify water by liberating 8 milligrams of iodine per tablet. The effects on thyroid size, function , and iodine uptake resulting from ingestion of four of these tablets daily for three months were studied in eight healthy volunteers. Thyroid size was determined by ultrasound. The thyroid-pituitary axis was assessed by bolus thyrotropin releasing hormone (TRH) tests. Urinary iodide levels increased from 0.276 to 40 mg/d. The mean RAIU fell and remained less than 2%. As thyroxine levels declined, basal thyroid stimulating hormone (TSH) and TSH response to TRH rose. In all subjects, thyroid volume increased. No clinical signs of either hyperthyroidism or hypothyroidism occurred. We conclude that in response to a sustained increment in TSH, the normal thyroid enlarges to adapt to the iodine from continuous use of tetraglycine hydroperiodide water purification tablets E R F PAGES RA II, Water quality