Table 1.

Range of iodine content µg/g DW of examples of the 3 main classes of edible seaweeds

Classification and species	Common names	Iodine content, µg/g DW (range)	Grams of seaweed required to achieve daily RNI of 150 µg/day
Green algae (Chlorophyta)
Undaria pinnatifida	Wakame	30–185	2.0–6.0
Ulva lactuca	Sea lettuce
Ulva intestinalis
Red algae (Rhodophyta)
Palmaria	Dulse, dillisk	20–200	0.3–3.0
Porphyra	Nori
Alaria	Irish wakame
Chondrus crispus	Irish moss
Brown algae (Phaeophyceae)
Laminaria Ascophyllum Fucoids	Kombu	2,500–10,000	0.01–0.04

These values were extracted from publications cited in this review [35, 37, 39] and are intended to give an indication of possible iodine intake arising from consumption of these seaweeds. As shown in the final column, consuming 1.0 g DW of red or green seaweed might not always achieve a daily RNI of 150 µg while an equivalent amount of brown seaweed would greatly exceed the TUL of 600 µg [5] or even the 900–1,100 µg per day recommended for adults or pregnant women [6]. DW, dry weight; RNI, recommended nutrient intake; TUL, tolerable upper level.