Supplemental Iodine is Safe

If you take a look at the scientific literature on iodine, and you’ll see frequent reports about the risk of hyperthyroidism from a too-high intake of iodine. This problem is relatively rare, and just about the opposite of what’s actually happening in the U.S. — an epidemic of hypothyroidism, with a widespread deficiency of iodine playing an important role.

So it was good to see a new study about iodine supplementation conducted by the same team of Spanish researchers who investigated the link between iodine levels and being overweight. They gave 30 people who didn’t have thyroid problems a daily dose of 100, 200 or 300 mcg of iodine. After six months, they found no affect on thyroid function — that is, the "extra" iodine didn’t cause hyperthyroidism. In fact, they found that it did the study participants a lot of good, because the mineral had both anti-inflammatory and antioxidant action. That's very important, because inflammation and oxidation are the evils twins behind many chronic diseases, like heart disease, cancer and Alzheimer’s.

References

"Iodine intakes of 100-300 μg/d do not modify thyroid function and have modest anti-inflammatory effects." Soriguer F, Gutiérrez-Repiso C, Rubio-Martin E, Linares F, Cardona I, López-Ojeda J, Pacheco M, González-Romero S, Garriga MJ, Velasco I, Santiago P, García-Fuentes E. Br J Nutr. 2011 Jan 25:1-8. [Epub ahead of print]