Nutrients & foods

Vitamins & minerals

Iodine

Is needed to make thyroid hormones.

Updated September 17, 2026 · Educational reference

What it does

Is needed to make thyroid hormones.

Possible deficiency symptoms

Low intake can contribute to an enlarged thyroid and impaired thyroid hormone production. Symptoms are not specific.

Food sources

Iodized salt; dairy; seafood; eggs. Seaweed iodine content varies greatly.

Supplement forms

Potassium iodide and sodium iodide.

Before taking a supplement

Excess iodine can also disrupt thyroid function. Kelp and high-dose iodine are not automatic treatments for fatigue.

Questions for your visit

Could my diet, medicines, absorption or another condition explain my concern? What evidence would support treatment, and how would we check whether it helps?

Names you may see

Iodine

Sources & perspective

This is an editorial adaptation of the Purser Wellness nutrient reference app. Purser teaching connections are labeled separately from clinical interpretation. Private cases and individual treatment protocols are not reproduced.

Use the public resources below for additional context.

NIH Office of Dietary Supplements: Iodine