Iodine Intake Calculator (Daily Needs by Age, Pregnancy & Breastfeeding)

How it works

Target = RDA (AI for infants) for the life stage · Share of target = intake ÷ target × 100 · Status compares intake with the target and the UL

Iodine is needed to make thyroid hormones, which control metabolism and drive the baby’s brain development in pregnancy. The National Academies’ RDA is 150 mcg a day for teenagers and adults, 220 mcg in pregnancy and 290 mcg while breastfeeding; infants have an Adequate Intake of 110–130 mcg. The adult upper limit is 1,100 mcg a day — too much iodine, for example from kelp supplements, can also disturb thyroid function. The main sources are iodized salt, dairy, eggs, fish and seaweed; the American Thyroid Association advises a prenatal supplement with 150 mcg of iodine.

Worked example

A woman aged 19–50 who is not pregnant gets about 120 mcg of iodine a day. Her daily target (RDA) is 150 mcg, so she covers 120 ÷ 150 = 80% and still needs 30 mcg — about a quarter teaspoon of iodized salt provides roughly 78 mcg.

Sources: NIH Office of Dietary Supplements — Iodine fact sheet for health professionals · Alexander EK et al. (2017) Guidelines of the American Thyroid Association for thyroid disease during pregnancy and the postpartum. Thyroid 27:315–389

Frequently asked questions