Iodine Supplementation: Usage “with a Grain of Salt”

Figure 2

Iodine “excess,” goiter, and hypothyroidism. On the one hand, chronic exposure to iodine excess can cause direct oxidative stress of thyroid cells by activation of the ROS cascade. On the other hand, the loss of downregulation of NIS leads to persistent high intracellular levels of iodine that causes reduction in thyroid hormone production.