Iodine goiter

Foodstuffs are not subject to regulations by the Health Authorities. In this category you find several seaweed products containing large amounts of iodine. It is recommended that these products should not contain more than 250 microg. of iodine per daily dose. These products are in several instances the cause of the many cases of iodine goiter and -myxedema and "Jod-Basedow reported in this country since 1962. In all urine samples examined for iodine excretion in the various investigations quoted in this paper, consumers of seaweed products have not been included. 

Thirty isotopes are recognized. Only one stable isotope, 1271 is found in nature. The artificial radioisotope 1311, with a half-life of 8 days, has been used in treating the thyroid gland. The most common compounds are the iodides of sodium and potassium (KI) and the iodates (KIOs). Lack of iodine is the cause of goiter. 

It is difficult to define the normal range of iodine intake in humans, and despite efforts to provide iodine supplementation in many geographic areas of the world, endemic iodine deficiency and attendant goiter remain a world health problem (147). Exposure to excess iodine may sometimes lead to the development of thyroid disease. This unusual type of iodide-induced goiter has been found, for example, in 10% of the population of a Japanese island where fishermen and their families consume large quantities of an iodine-rich seaweed and have an iodine intake as high as 200 mg/d (148). 

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. 

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. 

Isoflavones have been implicated in goiter induction. Soybean extracts inhibit reactions catalyzed by thyroid peroxidase (TPO), essential to the synthesis of thyroid hormones (Divi et al., 1997). Genistein and daidzein (at about 1-10 p,M of IC50) may act as alternative substrates for tyrosine iodination (Divi et al., 1997). Furthermore, genistein and daidzein have also been shown to cause the irreversible inactivation of TPO in the presence of hydrogen peroxide. Genistein also inhibits thyroxine synthesis in the presence of iodinated... 

Goiter A nonmalignant enlargement of the thyroid gland, visible as a swelling at the front of the neck, that is often associated with iodine deficiency. 

A number of dietary deficiencies may increase the risk of deleterious cyanide effects. Iodine deficiency is involved in the etiology of such thyroid disorders as goiter and cretinism. These disorders may be exacerbated by excess exposure to cyanide (Delange and Ermans 1971 Ermans et al. 1972). Protein deficiencies and vitamin B12, riboflavin and other vitamins and elemental deficiencies may subject people... 

Evidence of a different sort also indicates wide variability with respect to thyroid function. In endemic areas not all of the individuals exhibit endemic goiters, only certain individuals. These, it would be assumed, are individuals who for some reason connected with the production of thyroid hormone need more iodine than their fellows. Similarly, it may be noted that in areas where sea food is abundantly used and iodine is therefore relatively plentiful, there are still some individuals who develop simple goiter. 

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. 

Goiter enlargement of the thyroid gland as a consequence of inadequate dietary iodine. 

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. 

Gaitan E, Cooksey RC, Legan J, Cruse JM, Lindsay RH, Hill J (1993) Antithyroid and goitrogenic effects of coal-water extracts from iodine-sufficient goiter areas. Thyroid 3 49-53... 

Iodine takes part in the thyroid gland s hormone synthesis. Endemic goiter with hypothyreosis occurs under iodine deficiency as well as arterial hypertension. Iodine deficiency in pregnant women can cause... 

Thyroid suppression therapy of euthyroid goiter (B). The cause of goiter (struma) is usually a dietary deficiency of iodine. Due to an increased TSH action, the thyroid is activated to raise utilization of the little iodine avail-Liillmann, Color Atlas of Pharmacology 2000 Thieme All rights reserved. Usage subject to terms and conditions of iicense. 

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