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

Brazil nuts are widely used as a natural selenium supplement, but the selenium content in each nut varies enormously depending on soil conditions, region, and even individual trees. While selenium is essential for thyroid function, antioxidant defence, and overall health, both deficiency and excess carry serious risks. This article explains why Brazil nuts are so variable as a selenium source, what the safe daily intake looks like, and why testing your selenium levels is the most reliable way to know whether your intake is adequate, insufficient, or dangerously high.

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.

At 24, Dr. Kate Placzek was sleeping 16 hours a day and barely functioning — yet her standard blood tests came back normal. It took a TSH result in the mid-thirties to finally explain her debilitating fatigue. In this candid personal account, she shares her thyroid diagnosis, what she learned about optimal TSH levels, and why testing beyond TSH alone can make all the difference.

Iodine is an essential trace element required for thyroid hormone production, yet many people are unknowingly deficient. While iodised salt and seafood are well-known sources, dairy products, eggs, and seaweed also contribute significantly to daily intake. Changing dietary habits — including reduced milk consumption and the replacement of iodine with bromine in bread production — are quietly lowering iodine intake across the population. This article explains where dietary iodine comes from, why the body needs it, how it is absorbed and excreted, and how at-home urine testing can confirm whether your intake is adequate.

Reverse T3 (rT3) is one of the most misunderstood markers in thyroid testing. Often called the “hibernation hormone,” it is frequently claimed — without scientific basis — to block thyroid receptors and slow metabolism. In Part 2 of this series, Margaret Groves of ZRT Laboratory examines what the peer-reviewed literature actually says about rT3, when elevated levels are clinically meaningful, and how to interpret the T3/rT3 ratio in the context of a comprehensive thyroid assessment.