Iodized salt

You are responsible for determining the amount of KI in iodized salt and decide to use an D ion-selective electrode. Describe how you would perform this analysis using... 

Iodine. Of the 10—20 mg of iodine in the adult body, 70—80 wt % is in the thyroid gland (see Thyroid and antithyroid preparations). The essentiahty of iodine, present in all tissues, depends solely on utilisation by the thyroid gland to produce thyroxine [51-48-9] and related compounds. Well-known consequences of faulty thyroid function are hypothyroidism, hyperthyroidism, and goiter. Dietary iodine is obtained from eating seafoods and kelp and from using iodized salt. 

Approximately half of the iodine consumed is used to make potassium iodide (see Iodine and iodine compounds). Production of KI is almost 1000 t/yr. Its main uses are in animal and human food, particularly in iodized salt, pharmaceuticals (qv), and photography (qv). 

Iodized Salt. Iodized table salt has been used to provide supplemental iodine to the U.S. population since 1924, when producers, in cooperation with the Michigan State Medical Society (24), began a voluntary program of salt iodization in Michigan that ultimately led to the elimination of iodine deficiency in the United States. More than 50% of the table salt sold in the United States is iodized. Potassium iodide in table salt at levels of 0.006% to 0.01% KI is one of two sources of iodine for food-grade salt approved by the U.S. Food and Dmg Administration. The other, cuprous iodide, is not used by U.S. salt producers. Iodine may be added to a food so that the daily intake does not exceed 225 p.g for adults and children over four years of age. Potassium iodide is unstable under conditions of extreme moisture and temperature, particularly in an acid environment. Sodium carbonate or sodium bicarbonate is added to increase alkalinity, and sodium thiosulfate or dextrose is added to stabilize potassium iodide. Without a stabilizer, potassium iodide is oxidized to iodine and lost by volatilization from the product. Potassium iodate, far more stable than potassium iodide, is widely used in other parts of the world, but is not approved for use in the United States. 

Iodine deficiency in less developed countries is still a serious problem. Whereas, iodized and iodated salt technology is readily available and relatively inexpensive, market distribution conditions, as well as a lack of understanding by consumers, prevents iodized salt from reaching much of the population in less-developed countries. 

If the necessary iodine input is insufficient the thyroid gland enlarges in an attempt to gamer more iodine addition of 0.01% Nal to table salt (iodized salt) prevents this condition. Tincture of iodine is a useful antiseptic. 

Potassium iodide is added as a nutrient to prevent goiter, a thyroid problem caused by lack of iodine, and to prevent a form of mental retardation associated with iodine deficiency. A project started by the Michigan State Medical Society in 1924 promoted the addition of iodine to table salt, and by the mid-1950s three-quarters of U.S. households used only iodized salt. Potassium iodide makes up 0.06 percent to 0.01 percent of table salt by weight. Sometimes cuprous iodide—iodide of copper—is used instead as the source of iodine. 

When iodine dissolves in organic solvents, it produces solutions having a variety of colors. These colors arise from the different interactions between the I2 molecules and the solvent (Fig. 15.21). The element is only slightly soluble in water, unless I ions are present, in which case the soluble, brown triiodide ion, I,, is formed. Iodine itself has few direct uses but dissolved in alcohol, it is familiar as a mild oxidizing antiseptic. Because it is an essential trace element for living systems but scarce in inland areas, iodides are added to table salt (sold as iodized salt ) in order to prevent an iodine deficiency. 

People whose diets are sparse in seafoods are susceptible to iodine-deficiency diseases, which are easily prevented by providing iodine in the diet. Iodized salt, which contains 0.1% KI, performs this function. 

Many environmental factors have been implicated in the induction of autoimmunity. One dietary component, iodine, has been well studied as a factor that increases autoimmune thyroid disease.67 68 Based on studies in the OS chicken, the increasing prevalence of autoimmune thyroid disease observed in U.S. and Western European populations has been ascribed to increased use of iodized salt.69 Experimentally, it can be shown that iodinated thyroglobulin is a more potent autoantigen than the equivalent noniodinated molecule. Food additives or pesticides may also be important in contributing to the development of autoimmune disease in susceptible individuals.70... 

Iodism, 14 368 Iodized salt, 22 815-816 Iodoacetate, antiaging agent, 2 813 Iodoacetic acid, 1 143 Iodoacetyl/bromoacetyl methods, for... 

We have already cited evidence to indicate that iodine needs vary substantially from individual to individual. Not only does the thyroid hormone content of the blood show high inter-individual variation, but in endemic regions not all individuals exhibit simple goiter due to iodine deficiency. And, in nonendemic regions where the iodine content of the foods is sufficient for most individuals, there are still some who suffer deficiency. Furthermore, even the iodine in iodized salt is said to be sufficient to yield unfavorable results for some individuals. 

Potassium iodide (KI) is added to table salt (known as iodized salt) to help prevent enlargement of the thyroid gland, a condition known as a goiter. 

Trace amounts of iodine are required for a healthy body. Iodine is part of the hormone thyroxin produced by the thyroid gland. Thyroid secretions control the physical and mental development of the human body. A goiter, a swelling of the thyroid gland, is caused by the lack of iodine. Adding thyroid medication and iodized salt to the diet helps prevent this disease. Radioactive iodine (1-131), with a half-life of eight days, is used to treat some diseases of the thyroid gland. 

Iodized salt prophylaxis. Goiter is endemic in regions where soils are deficient in iodine. Use of iodized table salt allows iodine requirements (150-300 pg/d) to be met and effectively prevents goiter. 

Iodide or iodate are used to iodize salt. The level of salt iodization depends on per capita salt consumption, moisture, light, heat, and contaminants. The recommended daily iodine requirements are 50 pg for infants, 90 pg for children (2-6 yrs), 120 pg for schoolchildren (7-12 yrs), 150 pg for adults and 200 pg for pregnant and lactating women. 

Goiter due to iodide deficiency is best managed by prophylactic administration of iodide. The optimal daily iodide intake is 150-200 meg. Iodized salt and iodate used as preservatives in flour and bread are excellent sources of iodine in the diet. In areas where it is difficult to introduce iodized salt or iodate preservatives, a solution of iodized poppy-seed oil has been administered intramuscularly to provide a long-term source of inorganic iodine. 

Iodine is concentrated in humans by the thyroid gland to form the iodo-amino acid thyroxine, which is essential to normal health and development. Iodine is a rather rare element (crustal abundance 0.00003 weight %, cf. Table 1.1), so the thyroid gland has become very efficient at scavenging iodide ion. As iodine is deficient in the diet in some locations, a small amount of iodide ion is routinely added to commercial table salt ( iodized salt ). 

Numerous reports m the literature demonstrate the effectiveness of iodized salt in controlling the medical condition called goiter. Check out this site for historical case studies thatfirst pointed to this conclusion. Comparing the research efforts behind iodized salt and fluoridated drinking water makes for an interesting project. 

Iodine must be present in the normal diet to prevent iodine-deficiency goiter or cretinism, and iodine deficiency-related disorders are still a worldwide (although preventable) group of diseases that affect about 150 million people in at least 40 countries. The WHO sponsored a program to control these disorders by the year 2000 (1,2), and since 1990 there has been a remarkable progress in prevention of iodine deficiency disorders. However, by the year 2000 one-third of the population affected by iodine deficiency disorders still did not have access to iodized salt (3). 

Because of reports of severe hyperthyroidism after the introduction of iodized salt in two severely iodine-deficient African counties (Zimbabwe and the Democratic Republic of the Congo), a multicenter study has been conducted in seven countries in the region to evaluate whether the occurrence of iodine-induced hyperthyroidism after the introduction of iodized salt was a generalized phenomenon or corresponded to specific local circumstances in the two affected countries (46). Iodine deficiency had been successfully eliminated in all of the areas investigated and the prevalence of goiter had fallen markedly. However, it was clear that some areas were now exposed to iodine excess as a result of poor monitoring of the quality of iodized salt and of the iodine intake of the population. In these areas, iodine-induced hyperthyroidism occurred only when iodized salt had been recently introduced. 

Delange F, de Benoist B, Alnwick D. Risks of iodine-induced hyperthyroidism after correction of iodine deficiency by iodized salt. Thyroid 1999 9(6) 545-56. 

A number of observers in Europe and on this continent have drawn attention to the harmful effects that may result under some circumstances from the use of iodine. They have found that when it is employed for the prevention of goiter without due medicinal supervision, used in quack medicines or taken as iodized salt in irregular amounts for a long period, serious toxic symptoms may be provoked. 

Cobalt is a component of the vitamin B12 molecule but a deficiency of cobalt has not been demonstrated in poultry fed a diet adequate in vitamin B12. Therefore, supplementation with this element is not normally necessary. Diets containing no ingredients of animal origin (which contain vitamin B12) contain no vitamin B12. Therefore, poultry fed on all-plant diets may require dietary cobalt, unless the diet is supplemented with vitamin B12. In practice, many feed manufacturers use a cobalt-iodized salt for all species since cobalt is needed in ruminant diets. This avoids the need to stock separate salt types for ruminant and non-ruminant diets and the inclusion of cobalt provides some insurance in case the poultry diet is lacking sufficient vitamin B12. 

Cobalt-iodized salt is often used as a source of sodium, chloride, iodine and cobalt. 

Note Iodine is usually provided in the form of iodized salt. 

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