Hyperthyroidism patients most often ask: “Can I eat iodized salt” and “Can I eat kelp and seafood”. There are also some “old” hyperthyroid patients who ask their doctors for a certificate to buy non-iodized salt. There are even women who have had hyperthyroidism and still maintain a low iodine diet during pregnancy and breastfeeding. In addition, advice from doctors on a “low iodine” diet also adds to hyperthyroidism patients’ fear of iodine intake, as shown in a quote from a popular science article: “Hyperthyroidism patients should not eat seafood and seafood such as seaweed, shells, crabs, fish and shrimp, and should eat non-iodized salt. ” The problem of iodine nutrition for hyperthyroidism patients has really troubled patients, their families and even doctors. It can be seen that hyperthyroidism patients have “iodine” embarrassment. In fact, iodine nutrition, like other nutritional problems, has plagued mankind since ancient times. Earlier, human beings mainly fought against nutritional deficiencies, but modern people seem to be more interested in preventing over-nutrition. Iodine is the main trace element that concerns human growth and development, especially intellectual development. China used to be a country with serious iodine deficiency, and in order to ensure the prevention and control of mental defects caused by iodine deficiency disease, the state has adopted a policy of iodized salt for all people since 1994. It has been proved that the iodization of salt for the whole population has greatly reduced the occurrence of “cretinism”, and the overall IQ of children in China has increased by nearly 12 percentage points. The benefits of iodine supplementation in terms of population intelligence far outweigh the other disadvantages of excessive iodine, which can cause relatively small risks. After salt iodization, the incidence of iodine hyperthyroidism did increase transiently, and the doses of anti-hyperthyroid drugs were once on the high side, prolonging the control time of hyperthyroidism. As a result, some doctors often have to warn patients to avoid iodine-rich foods and iodized salt. However, from the worldwide experience with iodized salt, the increased difficulty in treating hyperthyroidism after salt iodization is an adaptation process for people in iodine-deficient areas to overcome the high iodine intake in the long term. This process, which occurs in many iodine-deficient areas after salt iodization, naturally returns to normal after 5-10 years as the iodine uptake of the thyroid gland and the long-term iodine supply of the population are brought into balance. But some poorly worded renderings and medical advice lacking medical theory have made the fear of iodized salt among hyperthyroid patients far from normal. Over 90 percent of hyperthyroidism is a disease called “diffuse goiter with hyperthyroidism”. These antibodies cause the thyroid gland to act like a wild horse, synthesizing more thyroxine than is physiologically necessary on its own without central instruction. Genetic factors, stress, anger, infection, overwork, and trauma are the main triggers for the development of hyperthyroidism. Iodine nutrition to meet daily physiological requirements is not a trigger for hyperthyroidism. Hyperthyroidism due to high iodine is often seen in people with severe iodine deficiency after rapid over-supplementation. Iodine hyperthyroidism without autoimmune involvement is often transient and often suggests a defect in the iodine metabolism of the patient. Because the normal human thyroid gland has a strong ability to self-adjust its iodine uptake and thyroxine synthesis to the level of iodine supply, when too much iodine is supplied in food, firstly, the iodine uptake by the thyroid gland is inhibited, and secondly, the synthesis and release of thyroid hormones are also inhibited, and excess iodine is excreted in the urine. On the contrary, when the supply of exogenous iodine is insufficient, the iodine transport mechanism will be strengthened and the synthesis and release of thyroid hormone will be increased, so that the secretion of thyroid hormone will not be too low, i.e. “one side of the land feeds one side of the people”. The World Health Organization recommends a daily iodine intake of 150-300 micrograms for adults. The average iodine content of iodized salt in China is about 30 mg/kg. Based on a daily salt intake of 5-10 grams per person, the daily iodine intake is about 150-300 micrograms, while the tolerable upper limit of iodine intake for adults is 600 micrograms to 1100 micrograms per day. After deducting the losses from cooking and human metabolism, the consumption of iodized salt is not higher than the WHO’s recommended iodine intake. Patients with uncontrolled hyperthyroidism are hyperactive in all aspects of iodine uptake, thyroxine synthesis, storage and release due to the action of antibodies. The key to treatment is the application of anti-hyperthyroid drugs to suppress all of these functions in excess, and in severe cases surgery or radioactive iodine therapy is required. “A low iodine diet is not helpful in the treatment of hyperthyroidism. Patients with controlled hyperthyroidism do not need to create their own iodine-deficient environment by deliberately not eating iodized salt or seafood for a long time. Once hyperthyroidism is cured and returned to normal diet, the iodine-starved thyroid gland is likely to have a strong iodine uptake function. Therefore, a deliberately low iodine diet may lead to a recurrence of hyperthyroidism. In particular, pregnant women who have suffered from hyperthyroidism should not intentionally eat a low iodine diet, which may cause fetal iodine deficiency and affect mental development. Because iodine is widely distributed in nature, rocks, soil, water, and air all contain trace amounts of iodine, and seafood such as kelp, seaweed, shellfish, and sea fish have the highest iodine content, followed by eggs, milk, and meat. As with the prevention of other excess nutritional diseases, a large amount of seafood and other animal foods can overload not only iodine, but also fat and protein. The key is to take effective therapeutic measures to control the thyroid function in a normal state in the long term. Therefore, hyperthyroid patients do not need to be embarrassed by iodine.