Minerals

Iodine

Iodine (I)

Strong

Iodine is essential for synthesizing thyroid hormones (T3 and T4), which regulate metabolism, growth, and development. Iodine deficiency is the leading preventable cause of intellectual disability worldwide. Salt iodization programs have reduced deficiency in many regions, but pockets of deficiency remain.

How It Works

Iodine functions primarily in thyroid hormone synthesis:

  • Thyroid Hormone Production: Iodine is incorporated into thyroglobulin and used to synthesize T4 (thyroxine, 4 iodines) and T3 (triiodothyronine, 3 iodines).
  • Metabolic Regulation: Thyroid hormones regulate basal metabolic rate and affect nearly every tissue.
  • Growth and Development: Critical for brain development, especially during pregnancy and infancy.
  • Thermoregulation: Thyroid hormones help regulate body temperature.
  • Cardiovascular Function: T3 influences heart rate and cardiac output.

Natural Food Sources

FoodAmount per Serving
Seaweed (nori and other varieties)16-2,984 mcg per sheet (varies widely)
Cod99 mcg per 3 oz
Cod71 mcg per 1/4 tsp
Iodized salt75 mcg per cup
Yogurt56 mcg per cup
Milk35 mcg per 3 oz
Shrimp24 mcg per large egg

Safety Information

Contraindications

  • Hashimoto’s thyroiditis – excess iodine may worsen autoimmune thyroid disease
  • Graves' disease - may worsen hyperthyroidism
  • Graves’ disease – may worsen hyperthyroidism

Potential Side Effects

  • Generally well tolerated at recommended intakes (rare)
  • Metallic taste, increased salivation (high doses) (uncommon)
  • Metallic taste and increased salivation at higher doses (uncommon)

Disclaimer: The information provided is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare provider before starting any supplement regimen.

Iodine | Natural Compare