Prevention of Micronutrient Deficiencies Tools for Policymakers and Public Health Workers (1998) / Chapter Skim
Currently Skimming:
5 PREVENTION OF IODINE DEFICIENCY
5 PREVENTION OF IODINE DEFICIENCY
Pages 167-202
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 167... ...
International! Councilfor the Control of Iodine Deficiency Disorders REQUIREMENTS FOR IODINE The thyroid hormones, thyroxin and triiodothyronine (T4 and T3)
|
From page 168... ...
When surgery is required or elected, the risks of surgery in the local setting must be considered, and these may not be negligible. Malignant degeneration is a much debated issue; there is probably a slightly increased risk in endemic goiter (Riccabona, 1972~.
|
From page 169... ...
The consequences of moderate degrees of iodine deficiency for cognitive and motor performance have been examined in great detail (Stanbury, 1994~. One of the earliest formal observations arose from the case of a village in rural, Andean Ecuador.
|
From page 170... ...
Physical Growth It has been difficult to prove a relationship between physical growth and iodine nutrition alone because of the confounding variables of the other deficiencies that are usually present in iodine-deficient regions (Greene, 1973~. Nevertheless, hypothyroidism (a consequence of iodine deficiency)
|
From page 171... ...
Uptake of iodine by the thyroid is an oxidative process, and energy is required for hormone synthesis and secretion. These processes require ironcontaining catalysts, but the role of iron deficiency in thyroid function is not well defined.
|
From page 172... ...
in representative samples from a population is presently the most convenient and reliable method to assess iodine nutritional status (Dunn et al., 1993a,b)
|
From page 173... ...
Measurements of TSH The technology of TSH measurements has advanced rapidly and Is becoming available for the assessment of iodine deficiency. There are easier and less expensive methods to detect iodine deficiency, but universal neonatal screening can provide a good ongoing indicator of iodine deficiency, and it can also monitor the adequacy of a continuing prophylactic program, provided the neonatal screening is universal.
|
From page 174... ...
These disorders were highly prevalent in the United States prior to the introduction of iodine through iodized salt. In the past, IDDs were frequent in much of Western Europe, and a severe problem in most Latin American countries, throughout most of Africa, in the Middle East, in the Himalayan region and southward on the subcontinent, in China, and in Southeast Asia.
|
From page 175... ...
The iodine content of salt should be measured
|
From page 176... ...
The iodine content of salt should be monitored on a daily basis at the factory or at the point of import and it should be frequently checked again at the store or point of sale, whereas little would be gained by measuring thyroid size more frequently than once each year. A national neonatal TSH screening program if universally employed-would provide continuous monitoring of the frequency of IDDs.
|
From page 177... ...
Importation of noniodized salt across borders has occasionally been a problem, especially when the product has been labeled as iodized but actually contains no iodine. Small traders or local producers of salt near salt deposits have been a problem in rural Bolivia, Ecuador, and Argentina, for example.
|
From page 178... ...
In some instances international agencies, particularly UNICEF, have been instrumental in introducing USI (universal salt iodization) and have assisted producers by supplying the machinery required for the ionization process.
|
From page 179... ...
Recently there has been renewed interest in intermittent dosage in classrooms using tablets or drops containing iodine. Iodinated Oil Iodinated poppy seed oil has been widely and successfully used in the prevention of IDDs since its introduction in the late 1950s in New Guinea (FierroBenitez et al., 1969; Hetzel et al., 19809.
|
From page 180... ...
NATIONAL PROGRAMS: SOME EXAMPLES OF SUCCESS AND FAILURE Ecuador Context There is evidence of the presence of endemic goiter in Andean Ecuador reaching back to pre-Columbian times. Goiter was occasionally mentioned over the years, and in 1957-1958, a national survey disclosed a remarkably high prevalence of goiter and cretinism.
|
From page 181... ...
The program with iodinated oil was initially extended to many villages in the highlands, with excellent results. Iodized salt has now replaced iodinated oil, and it reaches virtually all consumers.
|
From page 182... ...
A crash program was initiated in 1988, and a large campaign using iodized oil reached about 1.4 million persons and continued until USI became institutionalized. A few highly isolated communities remain where iodinated oil is still necessary.
|
From page 183... ...
In 1995 the government restored salt iodization' but no new national survey has been available. Results The failure of the program in Guatemala points to the disastrous results that follow failure of government support and when no established agency has taken the responsibility to be continuously mindful of the latent risks of iodine deficiency.
|
From page 184... ...
Results IDDs have vanished from the United States. Although iodized salt can be obtained in markets throughout the country, noniodized salt can be purchased as well, and there is no further pressure to use the iodized product.
|
From page 185... ...
A plant for salt ionization was established at the portal of entry in 1985, and it has slowly begun to iodize all salt at a level of 60 m=, I/kg. Administration of iodinated oil was initiated, and more than 50,000 injections were given along the border with India, where there was some infiltration of noniodized salt, but this program is giving way as tighter control of salt ionization is realized.
|
From page 186... ...
The lesson of the Zimbabwe experience is that whenever iodine supplementation or fortification is introduced into an iodine-deficient region, there will almost surely be a small number of subjects, especially those with nodular goiter of long standing, who develop thyrotoxicosis, and this occurrence must be anticipated. It is also evident that tight monitoring of the iodine content of salt from producer to consumer is needed, and the possible occurrence of iodine-induced thyrotoxicosis requires vigilance.
|
From page 187... ...
Assessment It should be the responsibility of the IDD commission or its equivalent to carry out the periodic assessments described above, including regular monitoring of iodized salt and its effects. In addition, there should be periodic assessments of IDD status by an external, independent team working with the local commission.
|
From page 188... ...
Legislation has failed because the responsible health officials have not advocated enforcement of the legislation enacted, because funds have not been appropriated, or because other health problems have been more pressing. There have been occasions when the salt industry has not been cooperative or the execution of legislation has not seemed practicable because of the dispersed nature of the salt industry and the difficulty of assuring compliance.
|
From page 189... ...
and needs more extensive review. Inadequate Involvement of the Salt Industry in Achieving Local or Universal Iodization of Salt As noted elsewhere, salt manufacturers have generally proved to be cooperative in iodizing their product.
|
From page 190... ...
surveys to enhance implementation of prophylactic programs or determine why they are less than successful. Long-term outcome of the children of mothers with multinodular iodinedeficient goiters who received iodinated oil during pregnancy.
|
From page 191... ...
These costs depend on many factors, includin, size, intervention chosen (iodinated oil or iodized salt) , level of monitoring, and the infrastructure available and its commitment and reliability.
|
From page 192... ...
Elimination of cretinism, improvement in general intelligence and neuromotor function, and an enhanced energy level are the dividends of the elimination of iodine deficiency. ACTION PLANS FOR THE INTERNATIONAL AGENCIES Independent Evaluation Evaluation of the current status of ID, IDDs, and the structure of country programs has been made in a few countries by independent external teams.
|
From page 193... ...
Research costs money, and the international agencies must recognize their obligation to support acquisition of new knowledge. (Examples appear elsewhere in these paragraphs.)
|
From page 194... ...
They require organizational effort and financial support. The former has come from ICCIDD or its regional representatives, but the financial support has come, and will continue to come, from the international agencies; private foundations, such as the Thrasher Research Foundation and Kiwanis; and industry, such as Merck Darmstadt and segments of the salt industry.
|
From page 195... ...
When the degree of IDDs demands a prophylactic program and iodized salt is not immediately available, iodinated oil may be given intramuscularly or orally as a long-term, interim preventative.
|
From page 196... ...
All salt for human and animal consumption in the regions where IDD is known or suspected is iodized at a recommended level at the factory. This will ensure that representative samples obtained regularly from retail outlets, or preferably from homes, have an iodine content sufficient to ensure a daily intake of 150 mg of iodine per person daily.
|
From page 197... ...
A national IDD program has been set up; it is responsible for continuous monitoring of the status of iodine deficiency and of iodine content of salt, according to established criteria. The responsibility also includes mandatory public reporting of IDD status at regular specified intervals (e.g., every 3 to 5 years)
|
From page 198... ...
In Endemic Goiter and Endemic Cretinism, J
|
From page 199... ...
In Endemic Goiter and Endemic Cretinism, .l.
|
From page 200... ...
1987. "When it rains it pours": endemic goiter, iodized salt, and David Murray Cowie, M.D.
|
From page 201... ...
201 Gutokunst R., Bcckcp We Hcrm~n, We cl hi.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.