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.
Child health and nutrition in Africa
Inadequacies in iodine intake on the other hand impair the synthesis of thyroid hormones, which are critical for normal development and proper functioning of the brain and nervous system as well as the conservation of body heat and energy. Iodine deficiency causes endemic goitre and cretinism as well as stunting of mental and physical development. Globally, 1.6 million people are at risk of iodine deficiency disorders and 50 million children affected by them. About 100,000 children are born each year with mental retardation, most of them in Africa. This is due to the low consumption of iodine-rich foodstuffs (e.g. marine products) and the over-consumption of foodstuffs causing goitre, particularly bitter cassava, which is a staple in Central Africa.