Kelp is rich in iodine. 100 grams of fresh kelp contains 114 micrograms of iodine, which is enough to meet the iodine requirement of an adult for one day. It can prevent diseases such as iodine-deficient goiter and is usually recommended to be consumed 1-2 times a week, about 100 grams at a time. Kelp, also known as longevity vegetables, is a large marine brown algae growing in low-temperature seawater, rich in potassium, calcium, unsaturated fatty acids, etc. It can remove cholesterol from blood vessel walls, promote digestion in the stomach and intestines, and has the effects of lowering blood pressure, lowering lipids, preventing tumors, anti-coagulation and anti-oxidation. Kelp is rich in dietary fiber and relatively low in calories, which is helpful for weight loss people. The brown surface of kelp contains glutamic acid, the content of which is 30 times higher than that of liver oil, which can promote children’s brain development. In addition, kelp is also rich in mannitol, which has diuretic and anti-swelling effects. Kelp is a cold food, so it is recommended that people with a cold spleen and stomach eat less of it to avoid aggravating spleen and stomach discomfort or causing diarrhea. Seawater contaminated kelp contains arsenic, which can lead to poisoning if consumed in excess.