Iodine
Iodine
Snapshot
Iodine is an essential trace element required for thyroid hormone synthesis, supporting metabolic rate, growth, and neurological development.
What is Iodine?
Iodine is a dietary mineral that the thyroid gland uses to produce thyroxine (T4) and triiodothyronine (T3), hormones that regulate cellular metabolism, energy production, and neurodevelopment.
Where It Comes From
Dietary iodine is found naturally in seafood (seaweed, fish, shellfish), dairy products, eggs, and iodized salt. In supplements, iodine is provided as potassium iodide, potassium iodate, or seaweed‑derived kelp.
Key Nutrients & Compounds
The active form is iodide (I⁻), which is oxidized to iodine (I₂) in the thyroid. Some supplements deliver molecular iodine or iodate, while kelp powders also supply trace minerals like magnesium and calcium.
Health Benefits
Adequate iodine intake supports healthy thyroid function, ensuring proper metabolic rate, thermogenesis, and energy levels. During pregnancy and early life, iodine is critical for fetal brain development and cognitive function. It also contributes to skin and hair health.
Recommended Dosage
The recommended dietary allowance (RDA) for adults is 150 µg per day; pregnant and lactating women require 220–290 µg daily. Supplementation typically provides 150–300 µg of iodine per dose.
How to Use It
Take iodine supplements with water, ideally with a meal. If using iodized salt, incorporate it into daily cooking. Seaweed powders can be added sparingly to foods for natural iodine and trace minerals.
Who Should Use It?
Individuals with low dietary iodine intake (e.g., limited seafood/dairy), pregnant or breastfeeding women, and those following vegan or low‑salt diets may benefit from iodine supplementation.
Possible Interactions or Cautions
Excess iodine can trigger thyroid dysfunction (hyper- or hypothyroidism) or immune‑mediated thyroiditis. Those with thyroid disease, autoimmune conditions, or on medications like amiodarone should consult a healthcare provider before supplementing.
Final Thoughts
Iodine is indispensable for thyroid hormone production and metabolic health. When consumed within recommended limits—via iodized salt, diet, or supplements—it ensures optimal energy balance and neurological development.
Scientific Studies
Zimmermann, M. B. (2009). Iodine deficiency. Endocrine Reviews, 30(4), 376–408.
https://doi.org/10.1210/er.2009-0011
Leung, A. M., Braverman, L. E., & Pearce, E. N. (2012). History of U.S. iodine fortification and supplementation. Nutrition Reviews, 70(10), 605–611.
https://doi.org/10.1111/j.1753-4887.2012.00529.x
Inaba, M., et al. (2005). Differential effects of iodide and iodate on thyroid hormone synthesis in human thyrocytes. Biological Trace Element Research, 103(1‑3), 13–24.
https://doi.org/10.1385/BTER:103:1:013