The following table presents the median urinary iodine concentration
(UIC) that indicates iodine status among different population
groups.
School age children
| < 20 |
Insufficient |
Severe iodine deficiency |
| 20-49 |
Insufficient |
Moderate iodine deficiency |
| 50-99 |
Insufficient |
Mild iodine deficiency |
| 100-199 |
Adequate |
Adequate iodine nutrition |
| 200-299 |
Above requirements |
May pose a slight risk of more than adequate iodine
intake in these populations |
| ≥ 300 |
Excessive |
Risk of adverse health consequences (iodine-induced
hyperthyroidism, autoimmune thyroid disease) |
Pregnant women
| <150 |
Insufficient |
|
| 150-249 |
Adequate |
|
| 250-499 |
Above requirements |
|
| ≥500 |
Excessive |
|
Lactating women and children under 2 years of age
| ≥500 |
Insufficient |
|
| ≥100 |
Adequate |
|
It is important to note that only population-level assessments of
iodine status are possible from the survey methodology of casual, spot
urine sample collection. Iodine status estimates based on the
methodology of casual spot urine sample collection cannot be used to
classify individual status and should not be presented as a prevalence
of deficiency or adequacy. The information provided in the table above
is frequently misinterpreted to reflect the situation of individuals.
The correct interpretation is that populations with a median urinary
iodine <20 microgram/L have “severe” iodine
deficiency, populations with a median urinary iodine 20-49 microgram/L
have “moderate” iodine deficiency, and populations with
a median urinary iodine 50-99 microgram/L have “mild”
iodine deficiency.
References
Urinary iodine concentrations for determining iodine status
deficiency in populations. Vitamin and Mineral Nutrition Information
System. Geneva: World Health Organization; 2013.
