Seaweed

Overview

Seaweed provides iodine, EPA (in red algae), glycolipids, magnesium, and fiber, supporting thyroid function and brain health.

Within the BRAIN Diet framework, seaweed can be added to soups, stews, or salads and provides trace amounts of creatine (e.g., nori) and taurine [1][2].

Key Nutritional Highlights

• Seaweed is a primary dietary iodine source supporting thyroid hormone synthesis [1]
• Marine algae contribute variable B12 analogues and should be interpreted cautiously for cobalamin status [2]
• Seaweed provides iodine, EPA (in red algae), glycolipids, magnesium, and fiber, supporting thyroid function and brain health. [1]
• Seaweed can be added to soups, stews, or salads and provides trace amounts of creatine (e.g., nori) and taurine. [2]
• Seaweed provides iodine, EPA (in red algae), glycolipids, magnesium, and fiber, supporting thyroid function and brain health.

Food Context

Synergies

• Part of diverse plant food strategy

Preparation

• Can be added to soups, stews, or salads
• Important for iodine intake (especially for plant-based diets)
• Low bioavailable EPA; consider algal oil for direct DHA

Essential Amino Acid Profile

Seaweed contribute plant protein. Pair with complementary protein sources (e.g. grains and legumes) for a balanced essential amino acid profile.

Recipes

no recipes found

Nutrient Tables (per 100 g)

Core nutrients

Nutrient	Amount per 100 g	% RDA per 100 g
Energy	43 kcal	—
Protein	1.7 g	—
Total fat	0.6 g	—
Saturated fat	0.2 g	—
Carbohydrates	9.6 g	—
Sugars	0.6 g	—
Fibre	1.3 g	—

Key vitamins and minerals

Nutrient	Amount per 100 g	% RDA per 100 g
Magnesium	121 mg	28.8%

Bioactive compounds

Explicitly identified compounds, including individual fatty acids, with a defensible quantity or an explicit qualitative status. Asterisks (*) identify supplementary sources below. Unquantified or trace constituents are not automatically admitted to the Substances list.

Compound / class	Amount per 100 g	Notes
Iodine	Present — quantity not established *	—

Source notes (supplementary):

• * Iodine: Seaweed is used as a dietary iodine source; iodine is often absent from USDA SR Legacy nutrient panels, so quantity is not established for this page.

Reference intakes: US Dietary Reference Intakes for adults (19–50 years; using the higher of male/female values where they differ).

Data provenance (core / micronutrient panel): USDA FoodData Central, Seaweed, kelp, raw, FDC ID 168457, SR Legacy bulk (April 2018), per 100 g edible portion, last checked 2026-08-15

Substances

Substances admitted through a supported nutrition-table row. Not every table row appears here. Cards are not BRS mappings.

2 substances in this food

I^-

Iodine

Thyroid hormone synthesis; neurodevelopment; neurotransmitter regulation

Mg²⁺

Magnesium

Enzymatic cofactor (>300 reactions); neurotransmitters; mitochondria; redox balance

References

[1] Seaweed is a primary dietary iodine source supporting thyroid hormone synthesis. Arterburn et al. 2008. Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid

[2] Marine algae contribute variable B12 analogues and should be interpreted cautiously for cobalamin status. Watanabe et al. 2002. Characterization and Bioavailability of Vitamin B12-Compounds from Edible Algae.