Iodine per Day from Salt

Daily Iodine Intake from Iodized Salt

Iodine is a trace element your thyroid can't do without; it needs iodine to make the hormones T3 and T4. To estimate how much you take in from iodized salt, the tool uses intake_µg = salt_g × iodization_mg_per_kg, which works because 1 mg/kg is the same as 1 µg/g. In Brazil, Law 6.150/1974 (regulated by ANVISA RDC 23/2013) requires that all table salt be iodized to between 15–45 mg of iodine per kg of salt. That single rule wiped out endemic goiter across most of the country.

The Recommended Dietary Allowance (RDA) set by the Institute of Medicine and adopted by WHO is 150 µg/day for adults. It climbs to 220 µg/day during pregnancy and 290 µg/day while breastfeeding, since the thyroid is working harder and passing iodine on to the fetus or infant. For children the figure is 90–120 µg/day depending on age. Adults shouldn't go past 1,100 µg/day.

Applications

It comes up in nutrition counseling and prenatal care, when tracking populations at risk of iodine deficiency disorders (IDD), and when checking whether a country's salt-iodization program is being followed. In Brazil the SUS hands out prenatal supplements with iodine when someone isn't getting enough from food. Marine fish, seaweed, dairy and eggs round out the natural sources.

FAQ

Can I get enough iodine without iodized salt? You can, but only if you regularly eat seafood, seaweed or fortified dairy. For most people, iodized salt is still the steadiest source.

Is excess iodine harmful? It can be. Taking in more than 1,100 µg/day over the long run may set off thyroiditis or even a paradoxical hypothyroidism (the Wolff-Chaikoff effect), particularly in people who are already susceptible.

Does this calculator replace medical advice? No. Treat it as an educational estimate built on official reference values. Pregnant women and anyone with thyroid disease should follow advice tailored to them by a doctor.