This is how you can test for iodine deficiency: >Simply put 1–2 drops of 5% Lugol’s solution (aqueous I2 and iodide) on a patient’s wrist, ideally early in the morning. The solution will create a yellow stain about the size of a half-dollar. Then simply have the patient monitor how fast the stain disappears. >The faster it fades, the more iodine-deficient he or she is. In a healthy patient with optimal iodine levels, the stain will be visible for 14–16 hours or even longer. If it’s gone in 2–3 hours, she’s got a significant deficiency. In essence, the test is showing to what degree the patient’s system is “hungry” for iodine. https://holisticprimarycare.net/topics/womens-health/qspotq-testing-iodine-levels/ Just some random website I found, but they explain the test well. >Deworming Down the rabbit hole you go - https://poal.co/s/Health/627192