TABLE 2.
Epidemiological criteria for assessing iodine nutrition in a population based on median and/or range of UI concentrations1
| Population | Iodine intake | Iodine nutrition |
| School-aged children2 | ||
| <20 μg/L | Insufficient | Severe iodine deficiency |
| 20–49 μg/L | Insufficient | Moderate iodine deficiency |
| 50–99 μg/L | Insufficient | Mild iodine deficiency |
| 100–199 μg/L | Adequate | Optimal |
| 200–299 μg/L | Above requirement | May pose a slight risk in the overall population, but likely to provide adequate intake for pregnant/lactating women |
| >300 μg/L | Excessive | Risk of adverse health consequences (iodine-induced hyperthyroidism, autoimmune thyroid disease) |
| Pregnant women | ||
| <150 μg/L | Insufficient | |
| 150–249 μg/L | Adequate | |
| 250–499 μg/L | More than adequate | |
| ≥500 μg/L | Excessive3 | |
| Lactating women4 | ||
| <100 μg/L | Insufficient | |
| ≥100 μg/L | Adequate | |
| Children <2 y old | ||
| <100 μg/L | Insufficient | |
| ≥100 μg/L | Adequate |
1
To convert from g iodine/L to μmol iodine/L, multiply by 0.0079. Reproduced with permission from (94). UI, urinary iodine.
2
Also applies to nonpregnant and nonlactating adults.
3
The term “excessive” means in excess of the amount required to prevent and control iodine deficiency.
4
In lactating women, the figures for median UI are lower than the iodine requirements because of the iodine excreted in breast milk.