Urinary iodine (UI) was measured in samples from adults in the Nutrition and Health Survey in Taiwan 2005–2008.
The median UI level was 100 μg/L, and the percentage of populations with UI levels below 100 μg/L and 50 μg/L was 50.1% and 15.1%, respectively, indicating that the iodine status was borderline adequate. Men had a higher UI level than women (102 μg/L vs. 98 μg/L, p = 0.003), and older individuals (age > 60 years) had a lower UI level than younger people, particularly in women. The iodine status of the population < 50 years was sufficient, but it was insufficient in older groups. Mild iodine insufficiency was noted in all areas of Taiwan except the Southern area and Penghu islands, with the lowest UI level of 79 μg/L in the Mountain area. Although the UI level of women of childbearing age (19–44 years) was 103 μg/L, there may be a risk of iodine deficiency during pregnancy.
The iodine nutrition of the Taiwanese population in 2005–2008 was borderline adequate, with insufficiency in some subgroups. Further monitoring of the iodine status is necessary.