A few figures about iodine and iodized salt: 150 micrograms of iodine per day for adults and 200 micrograms for pregnant women and nursing mothers. Salt contains 20-50 micrograms of iodine per gram, with a per capita daily salt intake of 6-8 grams. Drinking water contains 0-10 micrograms of iodine per liter. There are also various foods that contain iodine to a greater or lesser extent. Kelp is the king of iodine among common foods, containing 923 micrograms of iodine per 100 grams of wet kelp. 1. What are the possible diseases caused by excessive iodine intake? In the body, iodine is mainly enriched in the thyroid gland, and other tissues contain almost no iodine, which also shows that insufficient or excessive iodine intake mainly affects the function of the human thyroid gland. With more iodine, the thyroid gland secretes more thyroxine, which promotes the metabolism of energy and energy-related nutrients (proteins, fats, carbohydrates) in the body. The typical symptoms of people with hyperthyroidism (hyperthyroidism) are fear of heat, easy hunger and lethargy. Excessive iodine intake can cause not only hyperiodothyroidism, but also iodine goiter, iodine hypothyroidism, Hashimoto’s thyroiditis, iodine toxicity, etc. In children, it can lead to impairment of growth and intelligence level. 2. What foods are rich in iodine? Foods rich in iodine are not produced in high mountains, but in low-lying basins and oceans. Among them, seafood has the highest iodine content, especially kelp, jellyfish, seaweed, moss strips and mussels. Among land-based foods, animals are at the higher level of the food chain, and animal foods contain more iodine than vegetarian foods, which is the secondary concentration of iodine. At the top of the food chain, we complete the third level of iodine concentration in the body. If the diet is vegetarian, combined with a small range of food choices, less iodine is obtained. Because of this, iodine deficiency diseases ravaged the world during the poor years of the past. 3. Which areas of China have a high dietary intake of iodine and are not prone to iodine deficiency? Who should not consume iodized salt? High iodine content in water sources causes rich iodine in crops and livestock, resulting in excessive iodine intake in the population. High iodine goiter is distributed in the alluvial fan plain of the Yellow River, the Jinzhong plain of Shanxi, and the intersection of Jiangsu, Anhui, Henan and Shandong provinces in China, involving a population of 30 million. People in coastal areas consume more seafood, especially seaweed, and also consume more iodine. People in these areas do not need to consume iodized salt. If you already have a thyroid disease, you should also consult an endocrinologist about your choice of salt. If you are not sure about your iodine status, you may want to go to the hospital to have your urinary iodine checked, and you should not consume iodized salt if your urinary iodine exceeds 800 micrograms per liter.