Iodine deficiency disorder (IDD) refers to health issues caused by inadequate iodine intake, ranging from abortions and stillbirths to mental and physical retardation. Over two billion people worldwide are at risk of IDD, with iodine deficiency being the leading preventable cause of intellectual disabilities. Universal salt iodization, health education, and monitoring programs are recommended to prevent and control IDD.
2. INTRODUCTION
Iodine is essential for human health as it is a
constituent of thyroid hormones, which play an
important role in physical and mental development.
Iodine is one of the leading causes of preventable
mental retardation and brain damage in the world.
Iodine deficiency not only leads to goiter and
cretinism but also to a much broad spectrum of
disorders.
3. Iodine deficiency is the single most
common cause of preventable
mental retardation and brain
damage in the world. The deficiency
has an immediate effect on child
learning capacity, women's health,
the qualities of life in communities
and economic productivity.
The normal requirement of iodine
for human beings averages 150 Îźg
per person per day.
4. When people consume diet lacking
sufficient iodine several important
health consequences known as
iodine deficiency disorder (IDD) will
result.
Iodine deficiency is a major public
health problem for populations
throughout the world, particularly
for the pregnant women and young
children.
5. Definition
Iodine Deficiency Disorders refer to a
spectrum of health consequences
resulting from inadequate intake of
iodine. The adverse consequences of
iodine deficiency lead to a wide
spectrum of problems ranging from
abortion and still birth to mental and
physical retardation and deafness,
which collectively known as Iodine
Deficiency Disorders (IDDs).
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7. Most important consequences of the spectrum
of IDD are:
⢠Goiter
⢠Mental retardation
⢠Hypothyroidism
⢠Cretinism
⢠Increased morbidity and mortality of infants
and neonates
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8. Risk factors
Following is a list of potential risk factors that
may lead to iodine deficiency:
⢠Low dietary iodine
⢠Selenium deficiency
⢠Pregnancy
⢠Exposure to radiation
⢠Increased intake/plasma levels of goitrogens,
such as calcium
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9. ⢠Sex (higher occurrence in women)
⢠Smoking tobacco
⢠Alcohol (reduced prevalence in users)
⢠Oral contraceptives (reduced prevalence in
users)
⢠Perchlorates
⢠Thiocyanates
⢠Age (for different types of iodine deficiency at
different ages)
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10. Epidemiology
⢠Iodine deficiency is the single most important
cause of preventable mental retardation.
Globally more than two billion (or over 38% of
the population living in 130 countries) are
estimated to be at risk of IDD and 260 million
people in Africa are at risk and 150,000 are
affected by goiter.
Source: 2007
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11. Distribution of Iodine Deficiency in Developing
Countries
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12. According to WHO a goitre rate above 5%
constitutes a public health problem. A profile
analysis from different studies in different
countries showed that from all babies born to
iodine deficient mothers, 3% will have sever
mental and physical damage, 10% show moderate
mental retardation and the remaining 87% show
some form of mild intellectual disability.
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13. Iodine deficiency world wide
Proportion of Population
population with UI < 100
WHO Regions
with UI < 100 g/L g/L (in
(%) millions)
Africa 47.6 48.342
The Americas 14.1 9.995
Eastern
55.4 40.224
Medierranen
Europe 59.9 42.206
South East
39.9 95.628
Asia
Western
19.7 36.082
Pacific
Total 36.9 272.438
WHO, UNICEF & International Council for the Control of Iodine Deficiency Disorders
14. ESTIMATED POPULATIONS AT RISK AND PREVALENCE OF ENDEMIC GOITRE IN
EIGHT COUNTRIES OF THE WHO SOUTHEAST ASIAN REGION (numbers in 1000)
Country Total POP. Population at risk (TGR > 10%) Endemic goitre prevalence
Number % Number %
Bangladesh 97 438 37 150 38.1 10 225 10.5
Bhutan 1 446 1 466 100. 946 65.4
Burma 39 920 14 545 36.5 5 694 14.3
India 746 010 149 588 20.0 7.3
Indonesia 161 003 29 773 18.5 9 759 6.1
Nepal 16 386 15 099 92.0 7 555 46.1
Sri Lanka 16 099 10 565 65.6 3 112 19.3
Thailand 52 709 20 439 38.8 7 740 14.7
TOTAL 1 131 011 278 605 24.6 99 349 8.8
TGR = Total Goitre Rate (prevalence)
Percentages shown are percentages of total populationSource: Clugston and Bagchi (1985, p. 14) and for total population data UN
14
Demographic Yearbook 1981/1982
15. ⢠It is estimated that approximately 516 million people
in Asia are at risk due to environmental iodine
deficiency, with about 176 million actually goitrous.
In Nepal, about 14 million people are at risk of which
8 million are goitrous.
Source: Tyabji, R: The use of iodated salt in the prevention of iodine deficiency disorders â a
handbook of monitoring and quality control. UNICEF, ROSCA, New Delhi. January 1985.
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16. NEPAL
⢠Currently only 63% of households in Nepal are
using adequately iodized salt.
⢠The proportion of low UIE values (<100Οg/l)
was 39.1% (adult women and school-aged
children) .
⢠The prevalence of low UIE is highest among
women in the Terai zone. It is still high as a
public health problem in that group.
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17. Only 35% of the
respondents had heard
educational messages
about iodized salt and very
few of the respondents
(19%) knew about the
importance of iodized salt
for health.
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18. Iodine deficiency in pregnancy causes more than
200,000 babies a year in Nepal to be born
mentally impaired; even mildly or moderately
iodine-deficient children have IQs that are 10 to
15 points lower than those not deficient.
Source: A National Development Priority THE WORLD BANK
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19. Iodine deficiency disorders (IDD) affect an estimated 10
million Nepalese nationwide.
A Goitre prevalence of 41.5% among females and
38.4% among males among school-aged children 6-14
years.
Source: Nepal Micronutrient Status Survey -1998
20. The estimated percent of households consuming
salt with some iodine is 91%. The estimate of
households consuming adequately iodized salt
(15ppm or above) is 63%.
Sourced from the Between Census Household Information, Monitoring and Evaluation System 2000- BCHIMES.
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21. Prevention and Control of IDD
Iodine deficiency is a significant environmental
problem. Iodine is essential for the synthesis of
thyroid hormones and cannot be synthesized by
the body.
Leaching of iodine from the soil due to erosion of
heavy rain, deforestation, overgrazing and clearing
lead to loss of iodine from the soil and water.
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22. Subsequently the iodine content would be low
in water, animal and plant products originated
from such iodine deficient soils. Hence, an
iodine deficient environment requires the
continued addition of iodine.
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23. The following methods are intended
as a major strategy:
1. Food fortification:
⢠Fortification of foods with iodine is
an effective means of long-term
prevention and control of many
iodine deficiencies, and one that has
been shown to be cost effective in
many countries.
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24. ⢠Universal salt iodization
- Iodization of salt for both human and
livestock consumption is required
- Use iodized salt in the food industry
to the population on a continuous and
self sustaining basis
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25. 2. Supplementation
In areas with lack of transportation and
small salt producers are available
⢠Administration of iodized oil capsule
⢠Direct administration of iodine solution
such as Lugol's iodine at regular
intervals
⢠Iodization of water supplies by addition
of iodine solution
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26. 3. Health education
ďś Create awareness about the consequences of
iodine deficiency disorder, specially for high risk
groups (infants, pregnant and lactating women)
ďś Advise the people to use iodized salt for
household consumption
ďś Educate the public to eat iodine rich food
items like sea fish, kelp, etc and avoid
goiterogenic foods.
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27. 4. Set surveillance
technique to monitor
the distribution of
adequately iodized salt
in the community.
Severe IDD: a dwarfed cretin woman
with a barefoot doctor of the same age
from the Hetian district in Sinkiang
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28. Policy and legislation in Nepal
Legislation on IDD: Currently, there is legislation
concerning the status of IDD in Nepal. It was
enacted in 1999 and makes the iodization of salt
manditory at a level of 50 PPM of iodine at the
production level.
The legislation has not been significantly revised
since, although there are no published
government documents concerning IDD.
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29. Government Agency to Address IDD
There is legislation governing IDD in Nepal. It
was passed in 1955 and has been revised since.
Salt iodization is mandatory at the level of 20-60
ppm.
The agency that is responsible for addressing
IDD is the Nutrition Section, Child Health
Division, of the Department of Health Services
under the MOHP.
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31. Government actions in IDD
⢠Universal salt iodization as sole strategy to
address IDD.
⢠Distribution of iodized salt in remote districts
at subsidized rates.
⢠Implementation of Iodized Salt Social
marketing Campaign.
⢠Monitoring of iodized salt at the entry points,
regional and national levels.
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32. ⢠Evaluation of IDD status
through National Survey and
integrated mini- surveys for
Vitamin A, iodized salt and
deworming.
⢠Iodized salt warehouse
constructions in various parts
of country.
⢠Development of Iodized Salt
Act in 1998.
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33. Recommendation
⢠A monitoring system for IDD control and quality
control mechanisms must be established.
⢠All salt should be checked for its iodine content
and monitoring procedures should be carried
out on an on-going basis as part of routine
health assessments.
⢠Stability of Iodine in Salt
⢠National Nutrition Policy and Strategy should be
implemented properly.
⢠Quality assurance
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34. References:
⢠MODULE of Iodine Deficiency Disorders For the For the Ethiopian Health
Center Team.
⢠Monitoring and Evaluation System 2000- BCHIMES.
⢠U
⢠WHO, UNICEF & International Council for the Control of Iodine Deficiency
Disorders
⢠Nepal Micronutrient Status Survey -1998
⢠A National Development Priority THE WORLD BANK
⢠Tyabji, R: The use of iodated salt in the prevention of iodine deficiency
disorders â a handbook of monitoring and quality control. UNICEF, ROSCA,
New Delhi. January 1985.
⢠UN Demographic Yearbook 1981/1982
⢠Iodine deficiency disorders in nepal: monitoring and quality control of
iodated salt a report by m. G. KARMARKAR, ph.D. ,C. S. Pandav, m. D. ,All
india institute of medical sciences new delhi â 110 029,may â june 1985
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