Iodine sufficiency States

Before providing data from India, it is relevant to summarize the information from other countries recently making the transition from an iodine-deficient to an iodine-sufficient state. Studies from Greece, Turkey and Iran report an increase in the prevalence of antithyroid peroxidase antibodies in the population after iodine supplementation (Zois et ai, 2003 Bastemir et aL, 2006 Heydarian et ai, 2007). Interestingly, other studies have provided data to the contrary. For example, the introduction of iodized salt to severely iodine-deficient children did not provoke thyroid autoimmunity in a study conducted in Morocco (Zimmermann et ai, 2003). 

Development of iodine-induced thyroid dysfunction is influenced by a person s prior iodine intake. Cases of thyrotoxicosis being induced by contrast media are mainly reported in Europe or Australia, where dietary iodine levels are low, as described by Fradkin and Wolff (1983). Except for cases due to amiodarone, the incidence of iodine-induced hyperthyroidism is very low in regions where dietary iodine is adequate (Roti and degfl Uberti, 2001). Neonates treated with PVP-I often develop hypothyroidism in iodine-insufficient regions of Europe, but rarely do so in iodine-sufficient regions of the United States, as described by Brown et al. (1997). Thus, persons who five in areas where iodine is deficient in the diet are at risk of developing thyroid dysfunction induced by iodine-containing pharmaceuticals. 

Monitoring and tracking iodine sufficiency in the United States... 

The NHANES 111 (1988-1994) and NHANES 2001-2002, an ongoing survey representative of the US population, measure U1 excretion. It was determined that the US population is iodine sufficient according to the WHO criteria (HoUowell et at, 1998). Some subsets of the US population, however, especially women of childbearing age, had an increased prevalence of mild iodine deficiency. Despite the stabilization of median U1 in the United States, a subset of the general population is still moderately or severely iodine deficient, especially among pregnant and lactating women (Tables 115.1 and 115.2). 

From the supernatant liquor, the amylopectin fraction was precipitated by adding sufficient magnesium sulfate to afford a total concentration of salt of 13.0% by wt. Allowing the precipitated amylopectin to remain in contact with the salt solution for 14 hours proved to be sufficient to make it perfectly insoluble in cold water. The amylopectin was then obtained in the dry state by the same technique used for the amylose precipitate. Po-tentiometric titration with iodine at 25.0° and measurement of the intrinsic viscosity at 25.00° were applied in order to characterize both fractions. 

Iodine deficiency in the diet may result in enlargement of the thyroid gland (known as goiter). Iodized table salt sold in the United States usually contains 0.01 percent KI or Nal, which is more than sufficient to satisfy the 1 mg of iodine per week required for the formation of thyroxine in the human body. 

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