Hormone Health Hub: Expert Insights on Testing, Balance & Better Living — iodine and thyroid health

Iodine deficiency is a significant and underappreciated global health problem, with urinary iodine levels in many Western populations having fallen substantially over recent decades. As an essential component of thyroid hormones, iodine deficiency impairs thyroid function, promotes goitre, and has wide-ranging consequences for metabolism, cognitive development, breast health, and reproductive health. Women of childbearing age are particularly vulnerable. This article explains the causes and consequences of iodine deficiency, who is most at risk, and how at-home dried urine testing using ICP-MS analysis can accurately confirm your iodine status.

Many patients produce sufficient thyroid hormone yet still suffer from classic hypothyroid symptoms. Why? Because standard TSH testing misses the full picture. In this clinical guide, Jim Paoletti explains the functional approach to thyroid assessment — examining T4 production, TBG binding, T4-to-T3 conversion, cortisol interference, ferritin and vitamin D — and outlines exactly which tests are needed for a complete analysis.

Environmental pollutants are in the food we eat, the air we breathe and the water we drink — and in excess, they can profoundly disrupt thyroid hormone synthesis and action. This article explains how iodine and selenium deficiencies develop, how antagonists like bromine, arsenic and mercury exacerbate thyroid dysfunction, and why urine testing for these five elements can reveal the hidden environmental drivers of thyroid symptoms that standard blood tests miss.

Normal thyroid blood tests don’t always explain why patients still suffer from fatigue, cold intolerance, brain fog and weight gain. In this in-depth clinical article, ZRT Laboratory explains the critical role of selenium in thyroid hormone synthesis and T4-to-T3 conversion, how heavy metals like mercury and arsenic sequester selenium and inactivate protective antioxidant enzymes, and why this can trigger Hashimoto’s thyroiditis — even when TSH, T4 and T3 appear normal.

Iodine is an essential component of thyroid hormones T3 and T4, and plays a broader role in antioxidant defence and breast health. Yet many people are unknowingly deficient. This guide covers the recommended daily allowances for different life stages, the best dietary sources of iodine — from kelp to cod — and when testing your iodine and thyroid levels may be warranted.