Seafood sources of iodine

Iodine is found in a range of foods, the richest sources being fish and dairy products. The most important natural source of iodine in the human diet is from marine fish and other seafood products. Fish such as cod and tuna, seaweed, shrimp, and other seafood, are generally rich in iodine.

Seaweed is a concentrated source of iodine, but it can provide excessive amounts (particularly so in the case of brown seaweed such as kelp) and therefore eating seaweed more than once a week is not recommended, especially during pregnancy. White fish contains more iodine than oily fish.

The study by Institute of Nutrition, Directorate of Fisheries showed that the iodine concentration in fillet of salt water fish was 5 to 10 times higher than those of fresh water fish, with highest value of 920 μg I/kg wet weight for changu. The lowest iodine concentration in fillet was found in barbus from Lake Awasa with only 5–8 μg I/kg wet weight. The iodine concentration in skin was higher than in fillets and the iodine concentration in fillets seemed to increase with fish size. The samples of plant origin were, in general, low in iodine (Journal of Food Composition and Analysis Volume 10, Issue 3, September 1997, Pages 270-282).

Iodine is an essential micronutrient required for normal thyroid function, growth and development. Its deficiency and excess both have adverse consequences on the body through effects on the thyroid gland. The thyroid gland requires trapping about 50-75 micrograms (μg) iodine daily to maintain an adequate supply of thyroid hormones. When daily iodine intake is below 50 μg threshold, goitre may develop.
Seafood sources of iodine