|The Prevention and Control of Iodine Deficiency Disorders - Nutrition policy discussion paper No. 3 (UNSSCN, 1988, 130 p.)|
|4. METHODS TO CORRECT IODINE DEFICIENCY|
There is evidence of the effectiveness for one to two years of a single oral administration of iodized oil in South America (Watanabe et al., 1974), and in Burma (Kyve-Thein et al., 1978).
More recent unpublished studies in India and China reveal that the effect of iodized oil taken by mouth lasts only half as long as a similar dose given by injection.
Experimental studies on guinea pigs in China indicate that iodized oil taken orally is stored in adipose tissue while the iodized oil injected is stored at the intramuscular site of the injection. Absorption from the muscle is slower than from the adipose tissue. There is also a greater loss of iodine from oral administration route due to de-iodization in the stomach; the iodine is then absorbed but rapidly excreted through the kidneys. In general, there is an 85-percent loss of iodine within 72 hours of iodized oil taken orally, compared with a loss from an intramuscular injection of 30 percent in two weeks, and a loss of 96 percent within 72 hours from iodized salt (Wei Jun and Li Jianqun, 1985).
The production of iodized oil to take orally is clearly a different proposition from that intended for injection. The addition of an antioxidant would be feasible in the case of an oral preparation.
There is an urgent need to increase the production of iodized oil. At present the main, if not- the only, source in the Western world is Laboratoire Guerbet of Paris. This firm is engaged in the production of radio-opaque dyes and not orientated to the large-scale production of one particular preparation.
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Possible chemical methods for iodizing oil have been investigated by Dr. Trevor Morton of the CSIRO Division of Applied Organic Chemistry, Melbourne, Australia (Morton and Guillaume, 1984). A variety of vegetable oils with linoleic acid as a major constituent can be iodized. Studies with safflower oil (76.9-80.5 percent linoleic acid) indicated that satisfactory and cheap iodization can be achieved with iodide and phosphoric acid. Development of this methodology to an industrial scale is required to demonstrate feasibility. It would seem likely however, that large quantities of iodized oil can be produced, particularly for oral use, at a reasonable cost.