Nori
Overview
Nori is a red seaweed (Porphyra species) commonly used in sushi and Japanese cuisine. It is a primary dietary source of iodine, an essential trace mineral critical for thyroid function and brain development. Nori also provides supporting amounts of folate (B9) and non-heme iron, along with contextual contributions of magnesium, vitamin K, and carotenoids.
Within the BRAIN Diet framework, while nori may contain variable amounts of vitamin B12 depending on species and processing, it should not be relied upon as a sole B12 source. The seaweed polysaccharides and soluble fibre in nori contribute to gut barrier and microbiome modulation through cumulative, supportive effects [1][2].
Key Nutritional Highlights
- Seaweed foods may contribute variable vitamin B12 compounds; nori should not be relied on as a sole B12 source [1]
- Marine algae and seaweed are primary iodine sources critical for thyroid and brain development [2]
- Nori is a red seaweed (Porphyra species) commonly used in sushi and Japanese cuisine. [1]
- It is a primary dietary source of iodine, an essential trace mineral critical for thyroid function and brain development. [2]
- Nori also provides supporting amounts of folate (B9) and non-heme iron, along with contextual contributions of magnesium, vitamin K, and carotenoids.
- While nori may contain variable amounts of vitamin B12 depending on species and processing, it should not be relied upon as a sole B12 source.
Food Context
Synergies
- Part of diverse plant food intake strategy
Preparation
- Commonly used in sushi rolls and as a garnish
- Important for iodine intake, especially in plant-based diets
- Folate and iron contributions are context-dependent and work best as part of a varied diet
- Seaweed polysaccharides provide cumulative gut health benefits when consumed regularly
Essential Amino Acid Profile
Nori contribute plant protein. Pair with complementary protein sources (e.g. grains and legumes) for a balanced essential amino acid profile.
Recipes
Nutrient Tables (per 100 g)
Core nutrients
| Nutrient | Amount per 100 g | % RDA per 100 g |
|---|---|---|
| Energy | 35 kcal | — |
| Protein | 5.8 g | — |
| Total fat | 0.3 g | — |
| Saturated fat | 0.1 g | — |
| Carbohydrates | 5.1 g | — |
| Sugars | 0.5 g | — |
| Fibre | 0.3 g | — |
Key vitamins and minerals
| Nutrient | Amount per 100 g | % RDA per 100 g |
|---|---|---|
| Iron | 1.8 mg | 10% |
| Magnesium | 2 mg | 0.5% |
| Folate | 146 µg | 36.5% |
| Vitamin K | 4 µg | 3.3% |
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 * | — |
| Carotenoids | Present — quantity not established * | — |
| Vitamin B12 | Present — quantity not established * | — |
- * Iodine: Nori 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.
- * Carotenoids: Nori contains mixed carotenoids; USDA laver records may list individual carotenoids, but the class total is not a USDA field.
- * Vitamin B12: Nori is tagged for vitamin B12. Fortified products vary by brand; seaweed B12 may include analogues; abbreviated USDA panels may omit cobalamin. True cobalamin quantity is not established here.
Substances
Substances admitted through a supported nutrition-table row. Not every table row appears here. Cards are not BRS mappings.
7 substances in this food
Iodine
Thyroid hormone synthesis; neurodevelopment; neurotransmitter regulation
Iron
Oxygen transport; dopamine synthesis (tyrosine hydroxylase cofactor)
Magnesium
Enzymatic cofactor (>300 reactions); neurotransmitters; mitochondria; redox balance
Vitamin B12 (Cobalamin)
Methylation; myelin; mitochondrial odd-chain FA metabolism
Vitamin B9 (Folate; 5-MTHF)
One-carbon metabolism; methylation; homocysteine recycling
Vitamin K (Phylloquinone)
Phylloquinone (vitamin K1) from green plants; required for vitamin K–dependent carboxylation.
References
[1] Seaweed foods may contribute variable vitamin B12 compounds; nori should not be relied on as a sole B12 source. Watanabe et al. 2002. Characterization and Bioavailability of Vitamin B12-Compounds from Edible Algae.
[2] Marine algae and seaweed are primary iodine sources critical for thyroid and brain development. Arterburn et al. 2008. Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid