Iodine — Supplements
Essential trace element required for thyroid hormone synthesis and metabolic regulation.
Overview
Iodine is an essential trace element required for synthesis of thyroid hormones (T3 and T4), which regulate basal metabolic rate, growth, and development. The thyroid gland concentrates iodine via the sodium-iodide symporter (NIS) for thyroid hormone production. Iodine deficiency remains the leading cause of preventable intellectual disability worldwide. While iodized salt programs have largely eliminated severe deficiency in developed nations, mild-to-moderate insufficiency persists in certain populations, including those avoiding iodized salt or dairy.
Indications
- Thyroid hormone synthesis support
- Iodine deficiency prevention
- Pregnancy and lactation nutritional support
- Metabolic rate optimization
Mechanism of Action
Thyroid follicular cells actively concentrate iodide from blood via the sodium-iodide symporter (NIS)
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Iodine | 150 mcg | Once daily | As potassium iodide or kelp-derived; 220 mcg for pregnancy, 290 mcg for lactation |
Evidence Grade
GRADE C
Safety & Contraindications
- Excessive iodine (>1,100 mcg/day) can cause thyroid dysfunction (Wolff-Chaikoff effect)
- May trigger or worsen autoimmune thyroiditis in susceptible individuals
- Individuals with Hashimoto's thyroiditis may be sensitive to iodine supplementation
- High doses can cause metallic taste, salivation, and GI irritation