Myth-buster
A meta-analysis of 54,621 people found that excessive iodine intake (median 350 μg/L) was linked to a 13% higher odds of thyroid nodules — but that increase was not statistically significant, meaning it could be due to chance.
This is among the first large-scale analyses to test the link between high iodine and thyroid nodules, and the null result means the picture is still contested — don't treat this as settled evidence either way.
Researchers combined data from over 54,000 people and found that those with very high iodine levels (roughly double the adequate amount) had a slightly higher chance of having thyroid nodules — but the increase was small enough that it could have happened by random variation. The overall relationship between iodine and nodules appears U-shaped, with risk rising at both deficient and excessive levels, but the 'excessive' part of that curve wasn't statistically solid in this analysis.
Where this fits in the evidence
This is among the first studies we've indexed on Iodine for Increased Risk of Thyroid Nodule — treat it as an early signal until more research accumulates.
The study
- Meta-Analysis
- n = 54,621
- 2026-01-27
- Frontiers in endocrinology
This is a plain-language summary of a research finding, not medical advice. Pillser surfaces research signals to help you decide what's worth investigating — always consult a qualified professional before changing what you take.