The iodine content of marine life is very high. The foods with the highest iodine content are seafood, such as kelp, laver, fresh hairtail, dried clam, dried scallop, mussel, sea cucumber, jellyfish, lobster, etc. The iodine content in kelp is the highest, reaching more than 240 mg/kg in dried kelp; Followed by marine shellfish and fresh marine fish (about 800 μ g/kg).

Fruits containing iodine include cherries, oranges, bananas, tomatoes, pineapples, peaches, applesauce, pickled/pickled fruits, apples, lemons, watermelons and guavas.

However, the iodine content in salt is very small, and the more refined the salt is, the less iodine it contains, and the iodine content in sea salt is about 20 μ g/kg. If each person ingests 10 g of salt every day, only 2 μ g of iodine can be obtained, which is far from meeting the needs of preventing iodine deficiency disorders.

Iodine is one of the essential trace elements in human body. The total amount of iodine in healthy adults is 30mg(20~50mg), and the national standard for adding iodine to salt is 20-30mg/kg.