Iodine in biology
The U.S. Institute of Medicine (IOM) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for iodine in 2000. For people age 14 and up, the iodine RDA is 150 μg/day; the RDA for pregnant women is 220 μg/day and the RDA during lactation is 290 μg/day. For children 1–8 years, the RDA is 90 μg/day; for children 8–13 years, 130 μg/day. As a safety consideration, the IOM sets tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. The UL for iodine for adults is 1,100 μg/day. This UL was assessed by analyzing the effect of supplementation on thyroid-stimulating hormone. Collectively, the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes (DRIs).
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.