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Learn · Thyroid

Iodine, Serum

Measured in mcg/L

The raw material your thyroid builds hormone from. Too little and the gland cannot make T4; too much and it can shut itself down. One of the few nutrients where both ends of the range produce the same symptom.

What the numbers mean

These are the ranges BioForge works to. They are not the same as a lab's reference range, which is built from the general population rather than from people who feel well.

Low
<40 · Deficient
Optimal
52–109 · Adequate
High
>150 · Can suppress the thyroid

What moves Iodine, Serum

Rises with iodized salt, seaweed and kelp supplements, iodine contrast dye, and amiodarone. Falls with non-iodized salt and a diet low in dairy and seafood. Kelp supplements are the most common cause of an unexpectedly high result.

Related markers in Thyroid

This page is educational and is not medical advice. Ranges are general and do not account for your history, medications or symptoms — a single number never decides a protocol. Your results are interpreted by a licensed clinician alongside everything else about you. Back to the Learning Center

Results Start Here

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Every BioForge protocol starts from your own bloodwork. The first 15-to-30-minute call is free.

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