People in coastal areas generally have the habit of eating seaweed like kelp, seems to be the most difficult population with iodine deficiency. But, in fact, high dietary iodine intake regions of China inland, rather than coastal. Epidemiological surveys, Weihai, Yantai, Qingdao, a coastal city of Shandong are still iodine-deficient areas, only Shandong province to the West and Northwest, iodine-deficient areas. Therefore, the Shandong coastal residents on the whole still need enough through iodized salt in iodine, to protect a person;s normal physiological needs. For hyperthyroidism populations, it may be necessary to prevent excess, proper eating kelp seaweed. Our recommended intake of iodine is 150 micrograms per day for adults, and pregnant women to be a little more. Testing urinary iodine in iodine nutritional status of the most important indicators are, if over three hundred or four hundred urine iodine µg/l or higher, it is necessary to control the intake of iodine.