Oral iodized oil

It has also been mentioned that salt iodization efficacy, the preferred strategy for IDD, might be influenced by ID, because this disorder impairs thyroid metabolism (WHO, 2001, Zimmermann et al., 2000). It has been observed that two initial steps in thyroid hormone synthesis are catalyzed by Fe-dependent thyroid peroxidase (TPO). One Fe-defl-ciency anemia study in rats showed reduced TPO activity, and decreased plasma T4 and triiodothyronine (T3) levels (Hess et al, 2002). IDA may also alter the central nervous systems thyroid metabolism control, and reduce T4 to T3 peripheral conversion (Beard etal, 1998), modify nuclear T3 binding (Smith et al, 1994), and increase circulating thyrotropin (TSH) (Beard et at, 1990). The therapeutic response to oral iodized oil is impaired in children with IDA compared with Fe-sufficient children (Zimmermann et al, 2000). 

In an intervention study with schoolchildren 8—10 years old in Malawi, Furnee et al. (1997) examined the relationship of intestinal parasite treatment and oral iodized oil efficacy. Severely iodine-deficient schoolchildren with a single parasitic infestation, either A. lumbricoides (n = 44), hookworm (n = 42), or Entamoeba histolytica (n = 24), were randomly allocated to receive or not receive treatment before taking a 1ml oral supplement (490 mg Iodine) of iodized ethyl esters from poppyseed oil. After supplementation, urinary iodine concentrations were measured regularly, to define time intervals indicating moderate iodine deficiency before urinary iodine concentrations returned to 0.40 mmol/1. Treatment with metronidazole for E. histolytica increased the protection period from 2.0 to 21.0 weeks P < 0.05). For all untreated children, the duration effect was 9.2 weeks shorter P < 0.001) than for their treated peers (16.8 weeks). They concluded that, by interfering with absorption, intestinal parasitic infestations reduce the efficacy of oral supplementation with iodized ethyl esters (Table 52.8). 

Iodized oil has been used to conttol IDD in China for more than 20 years. It was initially administered by injections, which were replaced by oral iodized oil capsules (lOCs) in 1978 (Shu, 2002). The National Outlines for the Ehmination of IDD in China by Year 2000 , approved by the state council, clearly stated that salt iodi-zation should be the predominant solution, supplemented by iodized oil (Shu, 2002). This is particularly relevant in the western parts of the country, especially in Xinjiang... 

Oral iodized oil Proven efficacy 1 -year duration Resource-intensive... 

The use of oral iodized oil has been effective in improving iodine status in women of childbearing age and pregnant women living in remote areas or countries with poor infrastructure who suffer from moderate-to-severe iodine deficiency. 

Al. A. Bautista, P.A. Barker, J.T. Dunn, M. Sanchez, and D.L. Kaiser, The effects of oral iodized oil on intelligence, thyroid status, and somatic growth in school-age children from an area of endemic goiter, Amer. J. Clin. Nutr. 35 127 (1982). 

J.H.Lazarus, A.B.Parkes, R.John, M.N Diaye and S.G.Prysor-Jones, Endemic goitre in Senegal - thyroid function etiological factors and treatment with oral iodized oil, Acta Endocrinol, 126 149-154 (1992). 

Fisher, D. A. (1989). Upper limit of iodine in infant formulas. /. Njdr. 119,1865-1868-Fumee, C. A., Pfann, C. A., West, C-, Kaat, E, Heidc, D-, and Hautvasi, J. (1995). New model for describing urinary iodine excretion Its use fur comparing different oral preparations of iodized oil. Am, J, CHh, Nutr. 61,1257-1262. 

The observation of toxicity of iodine mainly focused on the iodide or iodate, which is normally present in iodized salt, milk, water and leachate of foodstuffs. However, the toxicity of some other species of iodine may be much higher than that of iodide and iodate. For the prevention of iodine deficiency disorders, iodized oil was used as an injection or administered orally in many countries iodized oil is normally produced by binding iodine atoms to the polyunsaturated fatty acid in the oil (Zimmermann et al, 2000). After administration, it was supposed that iodine is released gradually as iodide to maintain a constant supply of iodine to the body. Experience in the past decades shows that the utilization of iodized oil is safe. However, acute poisoning of iodized oil to children who are orally administered was reported in China in 1998 this may be related to the species of iodine, which may be more toxic than iodide or iodate. Iodine has been used as an effective, simple, and cost-efficient means of water disinfection (Backer and Hollowell, 2000), in which the active disinfectant species are elemental iodine and hypo-iodous acid. Doses of iodine below 1 mg/1 kill bacteria within minutes. Elemental iodine and hypoiodous acid remain in the disinfected water, which may be toxic to humans. 

Acute iodine supplementation is by oral potassium iodide or iodized oil. Long-term iodization is optimally achieved by iodized salt. 

Active prophylaxis (AP) is the provision of iodine supplements to an iodine-deficient population. Beside the individual supplementation of oral iodine and injections of iodized oil, the most common supplementation strategy is the iodization of salt, water and animal feed. Some countries allow only iodized salt to be sold, while other countries allow both iodized and uniodized salt. 

R.Tonglet, P.Bourdoux, T.Minga, and A-M.Ermans, Efficacy of low oral doses of iodized oil in the control of iodine deficiency in Zaire, N Engl J Med. 326 236(1992)... 

These results are grossly consistent with those obtained by JUN and JIANQUN in Guinea pigs with soybean iodized oils. These authors reported a 80 % urinary and fecal elimination of the oral dose within the 3 days post administration. 12 % of the dose is detected 7 days post injection in the whole body and rapidly eliminated from the fat storage sites. The author hypothetized a rapid deiodination occuring in the gastro intestinal tract and in the body. They did not conclude about the thyroid iodine uptake. However, our study demonstrated that unless a few percent (6 % at 7 days and less than 2 % at 90 days) of the injected dose is retained in the body, a similar iodide incorporation in T4 is observed for oral and intramuscular administration route at least 7 days post injection. No conclusion can be drawn about delayed T4 iodine incorporation as no quantification was possible at 90 days. 

Farm animal studies demonstrate that in normal large animals, the oral absorption of lipiodol causes a progressive increase in blood iodine levels. In iodine deficient pigs, a very rapid increase in blood iodine levels, which lasted 2,5 months, was observed. The clinical efficiency of the iodized oils therapy was strongly suggested by various authors who evidenced lamb goiter in Australia and New Zealand and successfully treated it by iodized oils . 

J.Wei and L.Jianquin, metabolism of iodized oil after oral administration in guinea pigs, Nutr Rep Int 31 1085-1092 (1985). 

The extremely high bioavailability of iodized oil given by the oral route is certainly also true for men. In addition, studies in animal provide well controlled experimental conditions and allow for adequate quantification of the data. However, the direct extrapolation to humans is hazardous, mainly because the physiology of the gastrointestinal tract is not comparable. Furthermore, this also depends from animal to animal, and is not the same at all when comparing, for instance, sheep to rat. 

The fecal excretion of iodine is minor if iodized oil is administered by the intramuscular route. If the oral administration is employed, we find that approximately 20 % of the administered dose is eliminated in the feces. 

A series of studies have evaluated the possible consequraces of transiait impairment of thyroid function during the neonatal period due to iodine deficiency. Studies conducted in areas with severe iodine deficiency have shown that there is a dramatic shift of the intellectual quotients (IQ) towards low values in schoolchildren bom to severely iodine deficient mothers. After the pioneer studies conducted in this field by the group of FIERRO-BENITEZ in Ecuador this concept has been confirmed by many others (Review in The same trend has also been illustrated in Europe BLEICHRODT et al. have showed that the frequency distribution of IQ in clinically euthyroid schoolchildren was also shifted towards low values in children from an iodine deficient area as compared to controls bom in the same type of rural villages but without iodine deficiency. This mental deficit was only partly corrected 32 months after the oral administration of iodized oil in the iodine deficient children. Consequently the deficit is due partly to hypothyroidism occurring in early life. Similar results were reported by others... 

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