You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Amount of population in the world who suffer iodine deficiency is: and explain in detail?
The World Health Organization (WHO) estimates that about 2 billion people are iodine-deficient, based on urinary excretion data. Iodine deficiency is prevalent in many mountainous regions and in central Africa, central South America, and nohern Asia. In areas of relative iodine deficiency, there is an increased prevalence of goiter and, when deficiency is severe, hypothyroidism and cretinism. Ref: Weetman A.P., Jameson J.L. (2012). Chapter 341. Disorders of the Thyroid Gland. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.