The choice of salt iodized or non-iodized depends on different specific situations. Hyperthyroidism patients need to eat non-iodized salt, and the general population needs to eat iodized salt. Because iodine is a necessary raw material for thyroid cells to synthesize thyroid hormones, iodine deficiency in the body can lead to a series of diseases called iodine deficiency disorders. Patients with iodine deficiency disease have no obvious clinical symptoms in the early stage. The thyroid gland is mildly to moderately diffusely enlarged, soft and painless. Very few people with significant enlargement may show symptoms of pressure, such as difficulty in breathing, difficulty in swallowing, hoarseness, irritating cough, etc. Iodine deficiency in pregnant women may lead to dull children. Some areas of China are iodine deficient, so iodized salt added to the daily consumption of salt can reduce iodine deficiency. Different iodine supplementation strategies are chosen according to different regions so as to meet the body’s iodine needs.