Can I eat too much seaweed?

Seaweed contains a lot of iodine. Not everyone can have the same amount of iodine. Here's what you need to know.
6 July 2022

Not everyone can tolerate a lot of iodine

Iodine is an essential mineral for the thyroid hormones. It is naturally rare in food. Seaweed does contain (a lot of) iodine. Seaweeds absorb this mineral very easily. Iodine is an excellent building material that most people do not have to avoid. Unless you are under 14, pregnant or have a thyroid disease. Then limit your iodine intake and read our recommendations on the packaging carefully.

How much seaweed can I eat?

Kombu absorbs the most iodine by far. Best use of kombu is as a kind of bay leaf and not to eat it. If you are sure, you can handle a lot of iodine. Then you can cut kombu into tiny pieces and eat it.

We recommend eating seaweeds up to 2-3 times a week and soaking and washing them before use. This is not necessary with TerraSana nori. Our seaweed man washes nori extensively a multiple times after the harvest.

arame seaweed japan, TerraSana


Upper limit iodine: what we recommend

The EFSA (European Food Safety Authority) recommends an upper limit of 0.6 mg iodine per day for adults. Preparation and use according to the instructions for use stated on the label.

Type of seaweed Maximum amount 
AO nori 15 g per day
Arame 2 g per day
Hiziki 1 g per day
Instant wakame 5 g per day
Kombu 5-6 cm per day
Nori 15 g per day
Nori crinkels 15 g per day
Sushi nori 15 g per day

Read more about iodine, what foods it is in and what it is good for here.

Other minerals in seaweed

Seaweeds feed themselves by absorbing nutrients from the sea directly into their cell walls. As a result, seaweed absorbs a lot of other minerals from the sea in addition to a relatively high dose of iodine. You will find calcium, magnesium, sodium, potassium, phosphorus and iron in a large part of the seaweeds. That is why they regularly get the label “superfood”!