Iodine is an element (atomic number 53) that is required by humans for the synthesis of thyroid hormones (triiodothyronine/T3 and thyroxine/T4). Chronic iodine deficiency can lead to numerous health problems in children and adults, including thyroid gland dysfunction (including goiter) and various neurologic, gastrointestinal, and skin abnormalities. Iodine deficiency in pregnant or nursing mothers can lead to significant neurocognitive deficits in their infants. "Cretinism" or severe mental retardation is a rare outcome of severe iodine deficiency during early development. Growth stunting, apathy, impaired movement, or speech/hearing problems may occur. Many individuals living in developing countries may be at risk of iodine deficiency and its complications, and iodine deficiency is considered to be a preventable cause of mental retardation. Iodine deficiency is rare in industrialized countries such as the United States, due to the enrichment of table salt and cattle feed with iodine. But deficiency is common in developing countries where supplementation may be considered. Humans obtain iodine from their diets. The amount of iodine in food or water depends upon the amount of iodine in the local soil. Areas with mountainous (glacier) water or heavy rainfall tend to be low in iodine content, increasing the risk of iodine deficiency. This review does not discuss medical uses of radioactive iodine or iodine contrast agents used for imaging studies such as computerized tomography (CT scanning).
Fucus vesiculosus is a brown seaweed that grows on the northern coasts of the Atlantic and Pacific oceans and the North and Baltic seas. Its name is sometimes used for Ascophyllum nodosum , which is another brown seaweed that grows alongside Fucus vesiculosus . These species are often included in kelp preparations along with other types of seaweed. The Vietnamese, as well as other Asian populations, consume seaweed as food in various forms: raw in a salad and as a vegetable, pickled with sauce or with vinegar, as a relish or in sweetened jellies, and also cooked for vegetable soup. As an herbal medicine, seaweed has been used for traditional cosmetics, treatments for cough, asthma, hemorrhoid, boils, goiters, stomach ailments, and urinary diseases, and for reducing the incidence of tumors, ulcers, and headaches. Vietnam has an abundance of algae floral with a total number of species estimated to be nearly 1,000 of which there are 638 species of marine algae identified.