The recommended daily intake of iodine varies by age, life stage, and region, but for most adults, it is 150 micrograms (mcg) per day. Pregnant women require more—220 mcg daily—and lactating women need the highest amount at 290 mcg per day to support infant development.
Recommended Daily Intake by Life Stage
Iodine needs change throughout life, with higher requirements during periods of growth and reproduction:
- Infants 0–6 months : 110 mcg (Adequate Intake)
- Infants 7–12 months : 130 mcg
- Children 1–8 years : 90 mcg
- Children 9–13 years : 120 mcg
- Teens 14–18 years : 150 mcg
- Adults 19+ years : 150 mcg
- Pregnant women : 220–250 mcg
- Lactating women : 270–290 mcg
Some organizations recommend slightly different amounts. For example, the World Health Organization suggests 250 mcg per day for pregnant women, aligning with international guidelines to ensure optimal fetal brain development.
Upper Limit and Safety
The Tolerable Upper Intake Level (UL) for adults is 1,100 mcg per day; exceeding this regularly may disrupt thyroid function. Long-term high-dose supplementation can lead to thyroid dysfunction, including both hyper- and hypothyroidism.
Dietary Sources
Most people can meet their iodine needs through a balanced diet. Key sources include:
- Iodized salt
- Seafood (e.g., cod, shrimp, seaweed)
- Dairy products (milk, yogurt, cheese)
- Eggs
- Some fortified plant-based milks
In regions like Ireland and the UK, the recommended intake is slightly lower at 140 mcg per day for adults, reflecting dietary patterns and public health strategies. In contrast, countries such as the United States, Australia, and New Zealand recommend 150 mcg for adults [
