Hashimoto's thyroiditis is an autoimmune thyroid disease, which can manifest in three thyroid function states: hyperthyroidism, euthyroidism, and hypothyroidism. The dietary requirements for iodized salt vary depending on the thyroid state. When Hashimoto's thyroiditis coexists with hyperthyroidism, an iodine-restricted diet is necessary. When thyroid function is normal in Hashimoto's thyroiditis, iodine intake should still be limited, as excessive iodine can cause a thyroiditis that changes from euthyroid to dysfunctional. Therefore, iodized salt can be consumed, but the intake of iodine-rich foods such as kelp, seaweed, and seafood should be restricted. When Hashimoto's thyroiditis coincides with hypothyroidism, iodized salt can be consumed without specific restrictions; both iodized and non-iodized salt are acceptable. This is because, at this stage, thyroid function primarily requires hormone replacement therapy, so the consumption of iodized salt has no effect.