Salt
The amount of iodine and the specific iodine compound added to salt varies from country to country. In the United States, the Food and Drug Administration (FDA) recommends [21 CFR 101.9 (c)(8)(iv)] 150 micrograms of iodine per day for both men and women. US iodized salt contains 46–77 ppm (parts per million), whereas in the UK the iodine content of iodized salt is recommended to be 10–22 ppm.
Iodine deficiency in China
The Chinese government implemented a program of regulating salt to contain iodine starting in 1995. A more recent study has confirmed that the availability of iodized salt in the provinces has increased since this date. Today, about one third of the Chinese population is living in areas with low concentrations of iodine in their water supply. Salt is available in China for less than the retail price in some other countries, at about 5 cents, and is consumed regularly in most diets. This is very cost effective for producers who now must abide by the iodized salt regulations and those for those who need to consume it. The black market, however, is laden with the non-iodized counterpart and partially accounts for the population still be fairly saturated with IDDs.