Iodine is an essential element and trace mineral that the body needs to utilise thyroid hormones. It regulates cell metabolism and plays a role in nearly every bodily function. Without enough iodine, a condition called hypothyroidism can occur, which typically causes weight gain, fatigue and depression. There are several natural food sources rich in iodine, which can help prevent the affliction.
Fish and seafood
While fish and shellfish can be great natural sources of iodine, the level of iodine contained in them may not always be easily determined. Many factors must be considered; for instance, the amount of iodine in the natural habitat and daily diet of the fish will have an impact on the levels of iodine in the fish's meat. 115g (4 oz) of wild fish may contain as little as 70 micrograms or as much as 1,000 micrograms of iodine.
Seaweed is known as a primary natural source, because of its high natural iodine content. Just one gram of dried brown algae contains 500 to 8,000 micrograms of iodine; one gram of the green or red variety provides 100 to 300 micrograms. The recommended daily requirement for healthy adults is currently 150 micrograms of iodine per day; therefore, the average healthy adult can satisfy their daily iodine requirement with a very small quantity of seaweed added to the diet.
Various studies have shown there is a significant level of iodine in milk in several countries, including the UK. However, the iodine content in dairy products, including milk, cheese and yoghurt, can vary according to how much iodine is used on the farm. Farmers give their cows iodine-fortified feed to prevent infection, and they use sanitising iodine solutions on their cows' udders and milking equipment.
Strawberries are a little-known source of iodine; they are known for many other essential vitamins, minerals and antioxidants, of which iodine is simply one among many. Strawberries are a good source of potassium, magnesium, Vitamin C, folate, thiamine and fibre. They make a good addition to an iodine-deficient diet because of the other nutrients they provide.
Although technically not a natural source of iodine, salt that has been fortified with iodine is an important and highly recognised source of dietary iodine. Unlike naturally iodine-rich foods that can vary greatly in iodine content, iodised salt is a more predictable source. Some of the richest sources of iodine are in fact processed foods and breads that have been made with iodised salt.