Iodine supplement

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). 

Sodium iodide is an iodine supplement in food, an expectorant, cloud seed to cause rain, and solubilizes iodine in aqueous solution for analytical work. The radioactive iodide salt of sodium, Na(I-131) is used to diagnose thyroid function. 

Angermayr L, Clar C. Iodine supplementation for preventing iodine deficiency disorders in children. Cochrane Database Syst Rev 2004. 

Juvenile or adult patients with primary hypothyroidism (as indicated by low serum free T4 and high serum TSH concentrations) are usually treated with thyroxine with the aim of relieving symptoms and reducing the serum TSH concentration into the normal reference range. If the primary hypothyroidism is the result of iodine deficiency, then gradually increasing dietary iodine supplementation may also be instituted in addition to the thyroxine replacement therapy. Iodine supplementation alone may lead to the development of acute hyperthyroidism. 

A summary of the occurrence and epidemiology of iodine-induced hyperthyroidism has been published (41), based on the authors experience in Tasmania, Zaire, Zimbabwe, and Brazil. Another review has more specifically examined the cardiac features of iodine-induced hyperthyroidism and has emphasized the importance of awareness, monitoring, and treatment of such hyperthyroidism in areas in which iodine supplementation has been recently introduced (42). 

Delange F. Risks and benefits of iodine supplementation. Lancet 1998 351(9107) 923-4. 

Delange F, Lecomte P. Iodine supplementation benefits outweigh risks. Drug Saf 2000 22(2) 89-95. 

Iodine deficiency is closely associated with the iodine content of the soils used in agriculture in the affected areas. Although iodine supplementation programs have eradicated iodine deficiency in many areas of the world, serious deficiencies still occur in certain regions-... 

Iodine supplements may lake the form of potassium iodide (KI) or potassium iodate The iodate anion is rapidly reduced to iodide in the body. The... 

Like niacin, niacinamide is indicated in the treatment and prevention of deficiency statc.s. Unlike niacin, niacinamide has no vasodilatory effect, which may be of therapeutic importance for compliance rea.sons. Niacinamide has no effect on uiglycerides and lipoproteins. This product is formulated with pota.ssium iodide and u.sed as an iodine supplement. 

Deficiency of iodine, a component of thyroid hormones, may result in goiter formation (see Chap. 73). However, not everyone with an iodine-deficient diet will develop a goiter. Thyroxine (T4) and triiodothyronine (T3) can be used to assess iodine status (see Table 135-8). Intravenous iodine supplements typically are not necessary except during long-term parenteral nutrition with minimal enteral intake. Iodine needs generally are met by cutaneous absorption of iodine from germicides (e.g., povidone-iodine) used in catheter care or consumption of iodized salt. " Use of povidone-iodine wiU likely decrease with the increased use of chlorhexidine for catheter care, and the need for iodine supplementation must be individualized. Iodine excess is rarely a clinical concern when thyroid function is normal. 

Moukarzel AA, Buchman AL, Salas JS, et al. Iodine supplementation in children receiving long-term parenteral nutrition. J Pediatr 1992 121 252-254. 

Cretins or other individuals with iodine or thyroid deficiencies may be more sensitive to adverse health effects from selenium exposure (Contempre et al. 1991b, 1992). Iodine supplementation of these individuals without selenium supplementation may further exacerbate the effects. The elderly may be less susceptible to the negative effects of selenium and more prone to selenium deficiencies. A number of researchers have reported lower absorption of selenium and lower selenium tissue concentrations in the elderly compared to younger adults (Martin et al. 1991 Morisi et al. 1989). 

Wichtel JJ, Craigie AL, Freeman DA, et al. 1996. Effect of selenium and iodine supplementation on growth rate and on thyroid and somatotropic function in dairy calves at pasture. J Dairy Sci 79 1865-1872. 

The autoimmune thyroid diseases, including Graves disease and Hashimoto thyroiditis, are some of the most common human autoimmune diseases (Pearce et al., 2003). These diseases are characterized by immune responses to thyroid antigen, resulting in infiltration of the thyroid by T cells and production of thyroid antibodies. However, the manifestations of these two entities are clearly different, and the two diseases are discussed separately. Furthermore, the effect of iodine supplementation on thyroiditis is discussed briefly. 

Hypothyroidism with goitre can result (rarely) from deficiency of iodine in the diet in which case treatment is with iodine supplementation. 

Without iodine supplements in the form of marine fishmeal or mineral mixtures, the farm animals of most countries worldwide would suffer of iodine deficiency. Germany and most industrially developed countries unconsciously supply farm animals (and in turn the population) with iodine by fertilizing the land with Chile saltpeter, which has a high iodine content. During World War I, the importation of Chile saltpeter to Europe was stopped, and thereafter synthetic nitrogen containing no iodine was produced worldwide. Consequently, iodine deficiencies in both animals and man reap-... 

Once iodine has been stored in the thyroid, high or excessive amounts of the element are excreted through the milk. This is the reason for the very high iodine concentrations seen in the milk of animals and ivomen after iodine supplementation (Table 9-4.6). 

Tab. 9.4-6 Infl uence of iodine supplementation on the iodine content of goat s milk (pg L ) (Anke et al. 1994)...

The natural iodine offer of animals and man without iodine supplementation greatly varies with distance from the seaside, the geological origin of the site, the eating habits and the specific iodine contents of the various foods and beverages (Table 9-4.15). The danger of an iodine deficiency is most severe in grazing ruminants (wild and domestic) and lowest in carnivores. Animals and people with mixed diets are also... 

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