Minerals
Evidence: strong_human
Iodine is the essential substrate for thyroid hormone synthesis. Thyroid peroxidase (TPO) uses iodine to iodinate tyrosine residues on thyroglobulin, producing monoiodotyrosine (MIT) and diiodotyrosine (DIT), which couple to form T4 (3,5,3',5'-tetraiodothyronine) and T3 (3,5,3'-triiodothyronine). Iodine is concentrated by the sodium-iodide symporter (NIS) in the thyroid, breast tissue, gastric mucosa, salivary glands, and choroid plexus. Beyond thyroid function, iodine has direct antimicrobial properties, modulates immune function, and may play a role in breast tissue health via iodolactone-mediated apoptosis.
Standard: 150-300 mcg daily (RDA: 150 mcg; upper range for optimization)
Loading: 12.5mg/day (Iodoral protocol — ONLY under practitioner supervision with selenium co-supplementation and thyroid monitoring)
Maintenance: 150-300 mcg/day
Administration: oral
Timing: Morning with food.
Duration: ongoing
SELENIUM FIRST RULE: Always ensure adequate selenium status (200 mcg/day selenomethionine) BEFORE initiating iodine supplementation. Iodine without selenium can trigger or worsen Hashimoto's thyroiditis by increasing TPO activity without adequate glutathione peroxidase protection (GPx3 in thyroid). The high-dose iodine debate (Brownstein/Abraham protocol at 12.5-50mg) is controversial — most endocrinologists do not recommend it. Conservative dosing (150-300 mcg) with selenium is the safe approach. Urinary iodine can be tested to assess status.
Potassium iodide (KI) is the most precise dosing form. Kelp-derived iodine varies in content and may contain heavy metals — less reliable. Nascent iodine (monatomic) has marketing claims but limited evidence of superiority. Lugol's solution provides both iodine and iodide. Brands: Life Extension Sea-Iodine, Pure Encapsulations Iodine, Optimox Iodoral (high-dose — practitioner only).
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