F&N Bulletin Vol 23 No 1b - United Nations University

Difference in goiter rates
iodized salt. Moreover, median urinary iodine excretion
values in both groups also demonstrated similarity
of level and adequacy of iodine intake. Thus, the
threshold of iodized salt intake deemed effective in
significantly lowering iodine-deficiency disorders may
be less than is usually assumed. However, it should
be pointed out that even regular users of iodized salt
in the two provinces showed a high rate of goiter
(31.3%), indicating a severe iodine deficiency in the
population. Although goiters in children respond
rapidly to iodine, those in adults are often associated
with chronic iodine-deficient status [12] and do not
disappear because they are fibrotic. Thus, a reduction
of goiter rates in an adult population may need time
[13], and a year of mandatory salt iodization may
produce no change [14]. Even those groups that use
iodized salt regularly need a longer time for goiter
rates to return to normal (less than 5%) [15].
We recommend that similar studies be implemented
in other countries, especially in areas that face difficulty
in expanding their salt-iodization programs
due to geographic barriers or political and economic
factors. If further studies confirm the effectiveness of
the occasional use of iodized salt in excess of more
than 10 kg per family annually in the prevention of
iodine-deficiency disorders, it could encourage the
93
government to adopt a different health-education
approach to the people who cannot afford to use only
iodized salt. Currently the criterion for adequacy of a
national salt-iodation campaign is 90% coverage [14].
However, the findings of our study and of other studies
should cause a reconsideration of the extent of iodized
salt coverage needed for success. Longitudinal studies,
with observation of participants over longer periods of
consumption, should now be implemented
Regular users of iodized salt consumed less salt. This
may have been because iodized salt costs three to seven
times more than noniodized salt in the areas studied.
In our previous study in 1996 [6], we speculated that
pregnant women who were highly aware of iodinedeficiency
disorders used more iodized salt because
they believed that it was better for their health. However,
this was contradicted by our salt-intake study
in 1998; pregnant women simply ate more food and
consequently consumed more salt [7].
Acknowledgments
The International Academic Promotion Fund in Hirosaki,
Japan, funded this research. We thank Mrs. C.
Bujin for her dedication in managing the study.
References
1. Hetzel BS, Pandav CS. SOS for a billion. Second edition.
New Delhi: Oxford University Press, 1997.
2. Hetzel BS. The iodine deficiency disorders. In: Delange
F, Dunn JT, Glinoer D, eds. Iodine deficiency in Europe.
A continuing concern. New York: Plenum Press, 1993:
25–31.
3. UNICEF Nutrition Section. Progress towards universal
salt iodization. New York: UNICEF, 1994.
4. Yamada C, Oyunchimeg D, Enkhtuya P, Erdenbat
A, Buttumur D, Umenai T. Current status of iodine
deficiency disorders in Mongolia. Asia Pacific J Public
Health 2001;12(2).
5. Yamada C. Analysis and evaluation of the National
Iodine Deficiency Disorders Elimination Program
and establishment of a sustainable community salt
iodization program in Mongolia. Doctoral dissertation.
Tokyo: University of Tokyo, 2001.
6. Yamada C, Oyunchimeg D, Igari T, Buttumur D,
Oyunbileg M, Umenai T. Knowledge, attitudes, and
practices of people in Ulaanbaatar, Mongolia, with
regard to iodine-deficiency disorders and iodized salt.
Food Nutr Bull 1998;19:353–8.
7. Yamada C, Oyunchimeg D, Erdenbat A, Enkhtuya P,
Buttumur D, Naran P, Umenai T. Estimation of salt
intake and recommendation of iodine content in salt in
Mongolia. Asia Pacific J Public Health 2000;12:27–31.
8. Delange F. Requirements of iodine in humans. In:
Delange F, Dunn JT, Glinoer D, eds. Iodine deficiency
in Europe. A continuing concern. New York: Plenum
Press, 1993; 5–13.
9. WHO/ICCIDD. Recommended normative values for
thyroid volume in children aged 6–15 years. Bull
WHO1997;54:95–7.
10. Waterlow JC. Classification and definition of proteinenergy
malnutrition. Monograph Series. Geneva: World
Health Organization, 1976;62:530–55.
11. Delange F, Benker G, Caron PH. Thyroid volume and
urinary iodine in European schoolchildren: standardization
of values for assessment of iodine deficiency. Eur J
Endocrinol 1993;36:180–7.
12. Pardede LVH, Hardjowasito W, Gross R, Dillion DHS,
Totoprajogo OS, Yosoprawoto M, Waskitol L, Untoro
L. Urinary iodine excretion is the most appropriate
outcome indicator for iodine deficiency at field conditions
at district level. J Nutr 1998:128:1122–6.
13. Kusic Z, Leckpammer S, Lukinac L, Petrovic I, Nothig-
Hus D. First beneficial results of the implementation
of Croatian new law on salt iodization. J Endocrinol
Invest 1999;22:747–51.
14. Jooste PL, Weight MJ, Lombard CJ. Short-term effectiveness
of mandatory iodization of table salt, at an
elevated iodine concentration, on the iodine and goiter
status of schoolchildren with endemic goiter. Am J Clin
Nutr 2000;71:75–80.
15. WHO/UNICEF/ICCIDD. Indicators for assessing
iodine deficiency disorders and their control through
salt iodization. Geneva: World Health Organization
(WHO/NUT/94.9); 1994.