Iodine

Iodine is small in quantity, but regulatory in function.

It is required for the synthesis of thyroid hormones,
which influence metabolism, energy balance, and systemic regulation.

At a high level, evaluation comes down to three signals:

• Dose range — narrow window between sufficiency and excess
• Source (iodide, kelp, etc.) — differences in consistency and variability
• Baseline intake context — existing dietary exposure and regional factors

Iodine is often included as a default component.
Its relevance is not uniform.

Both deficiency and excess can disrupt function.
Balance, not presence, determines outcome.