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

92 C. Yamada and D. Oyunchimeg
TABLE 1. Total annual consumption of salt, annual consumption of iodized salt, and consumption of iodized salt as a
percentage of total consumption by households grouped according to their consumption of iodized salt (means ± SD)
Total annual Annual
salt consump- consumption of
Household size
Group tion (kg) iodized salt (kg) % iodized salt Adults Children
1. Iodized salt only 21.9 ± 8.3 21.9 ± 8.3 100 2.6 ± 0.54 3.4 ± 0.8
2. >10 kg iodized salt annually 31.6 ± 12.1* 12.8 ± 1.5 46.2 ± 16.7 2.4 ± 0.9 3.1 ± 1.4
3. 6–10 kg iodized salt annually 30.5 ± 11.7* 7.9 ± 1.4 30.5 ± 15.2 2.4 ± 1.0 3.3 ± 0.3
4. < 6 kg iodized salt annually 29.7 ± 11.2* 3.9 ± 1.5 15.4 ± 8.9 2.8 ± 0.9 3.2 ± 0.8
5. No iodized salt 36.2 ± 11.4* 0 0 2.7 ± 0.6 3.6 ± 1.1
* Significant difference from group 1 (p < .001).
TABLE 2. Rate of goiter of children from households grouped according to household
consumption of iodized salt
Goiter 95% confidence
Group n rate (%) interval (%)
1. Iodized salt only 99 31.3 22.2–40.4
2. > 10 kg iodized salt annually 99 30.3 21.2–39.4
3. 6–10 kg iodized salt annually 96 40.6 30.8–50.4
4. < 6 kg iodized salt annually 94 52.1* 41.6–61.6
5. No iodized salt 297 56.6* 51.0–62.2
*Significant difference from group 1 (p < .01).
TABLE 3. Urinary iodine excretion (µg/L) of children from households grouped according
to household consumption of iodized salt
Group n Median Mean ± SD
1. Iodized salt only 99 82.0 95.5 ± 64.2
2. > 10 kg iodized salt annually 99 97.2 115.6 ± 65.9
3. 6–10 kg iodized salt annually 96 58.7 73.4 ± 58.8
4. < 6 kg iodized salt annually 99 56.2 70.7 ± 59.1
5. No iodized salt 297 29.5 43.4 ± 52.7
10 kg of iodized salt annually and those who used
6 to 10 kg annually were not different from that of
children from households that were regular users of
iodized salt. In contrast, the rates of goiter among
children from households that used less than 6 kg
of iodized salt annually or that used noniodized salt
were significantly greater than those of children from
households that regularly used iodized salt (p < 0.01).
Urinary excretion of iodine
The median values of the five groups are presented
in table 3. Only the children from households that
used noniodized salt had moderate iodine deficiency,
whereas the other four groups showed mild iodine
deficiency [9]. However, the median urinary iodine
excretion values in children from households that used
iodized salt regularly or that used more than 10 kg
annually were very close to normal (> 100 mg/L).
Discussion
These results indicate that when half of a household’s
salt consumption is iodized at current levels, this is
sufficient to prevent iodine-deficiency disorders in the
Mongolian population, but when less than one-third
of salt consumption is iodized, iodine-deficiency
disorders are not prevented. When between one-half and
one-third of household salt is iodized, goiter rates are
improved, even though iodine-deficiency disorders are
not fully prevented. There was no statistically significant
difference in the rate of goiter between children from
households whose annual consumption of iodized salt
was less than one-third of total salt usage and those
from households that used only iodized salt.
Children from households that purchased half of
their salt as the more expensive iodized form had a
reduction of goiter rate almost identical to that of
children from households that were regular users of