Eye on Wellness with Lynn Ray

02/03/2026

What is depression ?

01/28/2026

They said to avoid these, but… 👉

01/27/2026

01/27/2026

Your thyroid doesn’t run on one nutrient. It runs on a system.

Iodine and selenium are trace elements, but without them, thyroid hormone production and regulation break down.

Here’s the biology:

• Iodine is the structural backbone of thyroid hormones.
It is literally built into T4 (thyroxine) and T3 (triiodothyronine).
No iodine → no thyroid hormone synthesis.

• Selenium doesn’t build hormones, but it controls them.
Selenium is required for iodothyronine deiodinase enzymes, which convert inactive T4 into active T3 and regulate hormone turnover.
Selenium-dependent glutathione peroxidases also protect the thyroid gland from oxidative stress during hormone production.

• Tyrosine is the amino-acid scaffold that iodine binds to during hormone synthesis; without it, the process stalls upstream.

This is why iodine without selenium can be problematic, and why improving selenium status has shown benefits in multiple clinical settings related to thyroid and immune function.

Practical Intake Guide (Adults):

IODINE
• Target: 150 mcg/day
• Food sources: iodized salt, seaweed (small amounts), fish, eggs, dairy
• Caution: excess iodine without adequate selenium can strain the thyroid

SELENIUM
• Target: 55 mcg/day (up to ~100 mcg/day commonly used in studies)
• Food sources: Brazil nuts (1–2 nuts), seafood, eggs, whole grains
• Upper limit: 400 mcg/day

TYROSINE
• Typical intake: 500–1,000 mg/day from diet or supplementation
• Food sources: poultry, dairy, fish, legumes, nuts

Thyroid health isn’t about megadosing a single nutrient.
It’s about balance; supporting hormone synthesis, activation, regulation, and gland protection together.

PMID: 18686295