Heavy Metals & Thyroid Dysfunction Heavy Metals and Thyroid Dysfunction: The Overlooked Role of Hormone Transport and Cellular Signaling Most conversations about thyroid health focus on hormone production — iodine intake, T4, T3, and TSH levels. However, research in endocrine toxicology shows that in states of toxic burden, the deeper issue often lies upstream , at the level of hormone transport and cellular responsiveness , rather than hormone synthesis itself. This helps e
