Generally speaking, most of land plants's iodine content is low, with an average of no more than1.0 mg per kilogram, only.
The iodine content of spinach and celery is high, which can reach1.64 mg and1.60 mg per kg.
The iodine in seafood is several times as high as that in land plants, and some are as high as dozens of times. Usually, the iodine content of kelp we eat is10.0 mg per kilogram.
Marine fish and laver are also good foods to supplement iodine in daily life. Eating kelp regularly can not only supplement iodine in the body, but also ingest other kinds of trace elements, amino acids and vitamins. Therefore, only seafood is the food with high iodine content in nature, so we should pay attention to eating this kind of food at ordinary times, which is the best natural iodine supplement product.