Iodine deficiency lower the risk of cardiovascular disease have resulted in lower discretionary salt use at the table. Additionally, there is a trend towards consuming more processed foods in western countries. The noniodized salt used in these foods means that people are less likely to obtain iodine from adding salt during cooking. Goiter is said to be endemic when the prevalence in a population is > 5%, and in most cases goiter can be treated with iodine supplementation. If goiter is untreated for around five years, however, iodine supplementation or thyroxine treatment may not reduce the size of the thyroid gland because
Iodine whose main product is sodium nitrate. In total, they can contain at least 0.02% and at most 1% iodine by weight. Sodium iodate is extracted from the caliche and reduced to iodide by sodium bisulfite. This solution is then reacted with freshly extracted iodate, resulting in comproportionation to iodine, which may be filtered off. The caliche was the main source of iodine in the 19th century and continues to be important today, replacing kelp (which is no longer an economically viable source), but in the late 20th century brines emerged as a comparable source. The Japanese Minami Kanto gas field