The thyroid conversion problem: why normal TSH misses 30% of patients By Rohan Smith · Functional & Nutritional Medicine, Adelaide · Published May 11, 2026 Quick Answer Standard thyroid testing in Australia starts and often ends with TSH. That’s the pituitary signal — the hormone the brain releases to tell the thyroid to work harder….
Why Your Metabolism Slows When You Diet — Dieting drops your resting metabolic rate 15–25% within weeks. A 2023 trial showed zinc + selenium co-supplementation raised RMR by 22.9% during an 8-week hypocaloric diet while placebo fell.
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Hashimoto’s thyroiditis is an autoimmune condition in which anti-thyroid peroxidase (anti-TPO) antibodies may gradually damage thyroid tissue, potentially reducing thyroxine (T4) and triiodothyronine (T3) production. A functional medicine approach may complement conventional levothyroxine therapy by addressing modifiable factors such as selenium status, gut…
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Nutrient deficiencies in vitamin D, magnesium, iodine, and iron may contribute to weight loss resistance by impairing metabolic efficiency, hormonal regulation, and mitochondrial energy production. Research published in the International Journal of Obesity and Endocrine Reviews suggests that correcting these insufficiencies through targeted…
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Thyroid dysfunction may contribute to anxiety, panic symptoms, and low mood even when standard TSH blood tests appear normal. Thyroid hormones such as triiodothyronine (T3) and thyroxine (T4) influence neurotransmitters including serotonin, dopamine, and GABA, as well as hypothalamic-pituitary-adrenal (HPA) axis signalling. Subclinical…
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Persistent fatigue, brain fog, weight changes, and low mood may occur even when thyroid-stimulating hormone (TSH) levels appear normal on standard pathology testing. Thyroid function depends on multiple factors beyond TSH, including T4-to-T3 conversion by deiodinase enzymes, selenium and zinc availability, hypothalamic-pituitary-thyroid (HPT)…
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Thyroid disorders in children — including congenital hypothyroidism, Hashimoto’s thyroiditis, and Graves’ disease — can impair growth, neurodevelopment, and emotional regulation. Thyroid-stimulating hormone (TSH) and free thyroxine (free T4) testing may identify dysfunction early. Standard medical treatment remains essential, while supportive functional medicine…
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Chronic stress may disrupt thyroid function through elevated cortisol, which can impair the conversion of thyroxine (T4) into active triiodothyronine (T3) via deiodinase enzymes while increasing reverse T3 production. Prolonged hypothalamic-pituitary-adrenal (HPA) axis activation is also associated with immune dysregulation that may trigger…
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Thyroid Stimulating Hormone (TSH) alone may not reveal the full picture of thyroid health. Markers such as Free T4, Free T3, Reverse T3 (rT3), anti-TPO antibodies, and anti-thyroglobulin antibodies can help identify impaired thyroid hormone conversion, autoimmune thyroid disease (including Hashimoto’s thyroiditis), and…
Author: Rohan Smith | Functional Medicine Practitioner | Adelaide, SA Quick Answer Chronic low-grade inflammation may disrupt insulin signalling, leptin sensitivity, and resting metabolic rate, creating a self-reinforcing cycle that promotes fat storage and makes weight loss increasingly difficult. Research by Gokhan Hotamisligil at Harvard Medical School has identified tumour necrosis factor-alpha (TNF-alpha) and interleukin-6…
