Theodore Zava, a research associate at ZRT Laboratory, was recently published in the Townsend Letter for his work with iodine testing.
The Townsend Letter article summarizes a study done with ten volunteers from ZRT Laboratory, five men and five women with no history of iodine supplementation. The goal in this study was to analyze urine iodine excretion kinetics before and after a 50 mg iodine/iodide loading dose and to investigate the arbitrary iodine loading test cutoff of 90% excretion used to determine whole-body iodine sufficiency.
It was determined that high urine iodine excretion continues after the 24 hour loading test period, resulting in low urine iodine recovery during the first 24 hours. This explains the high failure rate of the iodine/iodide loading test, even after supplementation with high dose iodine. It was recommended to the creators of the iodine loading test that the arbitrary test cutoff is lowered, and that iodine excretion in feces and sweat be examined.