How does high, variable iodine intake from kelp specifically impact individuals taking the synthetic thyroid hormone levothyroxine?

Fluctuating dietary iodine levels can throw off required dosage levels, potentially causing under- or overdose symptoms.

Levothyroxine is synthetic thyroid hormone replacement therapy used to manage hypothyroidism, requiring precise dosing to maintain systemic balance. Because kelp consumption introduces high and highly variable amounts of natural iodine, it directly interferes with the regulated system. This fluctuating dietary iodine load can disrupt the balance that the medication is meant to maintain, meaning the required dosage level of the synthetic hormone might become inadequate or excessive, potentially leading to symptoms associated with insufficient treatment or symptoms indicative of an overdose. This necessitates frequent and disruptive adjustments to the prescribed medication regimen.