You generally need only a very small amount of iodine per day, and most people can meet it through food if their diet is varied and includes iodized salt, dairy, seafood, or fortified foods.

Daily iodine needs

Typical recommended daily intakes (RDA/RDI) of iodine are:

  • Adults (men and women 19+): about 150 micrograms (mcg) per day.
  • Teens 14–18 years: 150 mcg per day.
  • Children 9–13 years: about 120 mcg per day.
  • Children 1–8 years: about 90 mcg per day.
  • Infants under 1 year: about 110–130 mcg per day (usually from breast milk or formula).

Special situations:

  • During pregnancy: around 220 mcg per day.
  • While breastfeeding: around 270–290 mcg per day.

Many national guidelines are in this same range (for example, 140–150 mcg per day for adults in the UK and Nordic countries).

Safe upper limit (how much is too much?)

There is also a “tolerable upper intake level” (UL), which is the highest daily amount unlikely to cause harm for most adults.

  • Common UL for adults: about 600–1,100 mcg (1.1 mg) per day, depending on the authority.

Regularly going far above this (especially with high-dose supplements or large amounts of seaweed/kelp) can stress the thyroid and increase the risk of thyroid problems in some people.

How people usually reach this amount

Typical contributors to daily iodine intake include:

  • Iodized table salt
  • Dairy products (milk, yogurt, cheese)
  • Seafood (fish, seaweed, shrimp)
  • Eggs
  • Fortified breads or plant milks in some countries

For many omnivores, a small amount of iodized salt plus normal dairy/egg/seafood intake already meets 150 mcg per day.

People at higher risk of not getting enough iodine include:

  • Vegans or strict plant-based eaters who avoid iodized salt and seaweed
  • People in areas where iodized salt is not widely used
  • Those on very low‑salt diets who also avoid seafood and dairy

Quick practical takeaway

  • Aim for about 150 mcg per day as a healthy adult, more if pregnant (220 mcg) or breastfeeding (around 270–290 mcg).
  • Avoid long‑term intakes above roughly 600–1,100 mcg per day unless specifically directed and monitored by a clinician.
  • If you are vegan, have thyroid disease, are pregnant, or are thinking about an iodine supplement or high‑iodine seaweed/kelp products, it is safest to check with a healthcare professional first.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.