Iodine (serum or urine)

Specialist

also —

What it isIodine is a halogen the thyroid uses to build T4 and T3. The body has no other meaningful use for it.

DoesProvides the essential building block of thyroid hormone.

GoodMid-range iodine supports thyroid hormone synthesis.

BadDeficiency causes goiter and hypothyroidism. Excess iodine — particularly in those with autoimmune thyroid disease — can trigger or worsen Hashimoto's.

Standard

40–92 µg/L serum; 100–200 µg/L urine spot.

Optimal

60–80 µg/L serum, 100–200 µg/L urine spot (narrow target)

Modifiers

Modern Western diets often borderline; salt iodization varies by region.

How to optimize

Lifestyle: —
Diet: Seaweed (kelp, nori — be careful, very concentrated), seafood, eggs, dairy, iodized salt.
Supplements: Use cautiously — most adults don't need supplemental iodine; avoid mega-doses, especially in autoimmune thyroid disease.
Peptides: —
Drugs: —

within Minerals