Sea Moss Mineral Density and Electrolytes

The single most repeated claim about sea moss is that it "contains 92 of the 102 minerals the human body needs." That number is everywhere — on product labels, in influencer videos, on the back of branded sea moss gel jars, and in countless wellness articles. It is also untraceable. No peer-reviewed analysis has ever validated it; the figure appears to originate with the late Dr. Sebi's marketing materials and has been copied forward without verification. What sea moss actually contains, per published laboratory analyses, is a respectable but not extraordinary spread of macro- and trace minerals dominated by potassium, calcium, magnesium, iodine, and sulfur, with measurable amounts of iron, zinc, manganese, copper, and selenium. It also — less marketed — bioaccumulates heavy metals from its growing water, with cadmium, inorganic arsenic, aluminum, and occasionally lead reported at concentrations that matter for daily consumption. This page replaces the "92 minerals" folklore with what USDA FoodData Central and the peer-reviewed phycology literature actually report, compares sea moss to ordinary whole-food mineral sources gram-for-gram, and walks through the harvest-region, wildcrafted-versus-farmed, and processing variables that determine whether a given serving is mineral-rich nutrition or a chronic low-dose toxin exposure.

Table of Contents

  1. The "92 Minerals" Claim and Where It Actually Comes From
  2. What Sea Moss Actually Contains (USDA + Peer-Reviewed Data)
  3. The Macrominerals: Potassium, Calcium, Magnesium, Sulfur
  4. Trace Minerals: Iron, Zinc, Manganese, Copper, Selenium
  5. Sea Moss as an Electrolyte Source: Real Numbers
  6. The Heavy-Metal Problem: Cadmium, Arsenic, Lead, Aluminum
  7. Wildcrafted vs Pool-Cultivated Sourcing
  8. Processing Methods and Bioavailability
  9. Comparison to Whole-Food Mineral Sources
  10. Practical Sourcing and Testing Guidance
  11. Key Research Papers
  12. Connections

The "92 Minerals" Claim and Where It Actually Comes From

Walk into any health-food store, search any sea moss product on Amazon, scroll any sea moss TikTok, and the same phrase recurs almost verbatim: "Sea moss contains 92 of the 102 minerals that make up the human body." The number is so widely repeated that most consumers assume it must come from a published analysis. It does not. There is no peer-reviewed paper, no USDA dataset, no government laboratory, and no academic phycology reference that supports the figure. The closest anyone can trace the claim is to marketing materials associated with the late Alfredo Bowman (Dr. Sebi), who sold a proprietary sea moss product and popularized the "92 of 102 minerals" phrasing in the 1990s and 2000s. From there it propagated through reseller copy, was repeated in social media, and eventually became a default fact-claim on countless product labels and influencer scripts.

The claim has two separate problems. First, the "102 minerals the human body needs" figure is itself fictional — the human body is built from about 25 chemical elements, and only 14 of these (calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, iron, zinc, copper, manganese, iodine, selenium, molybdenum, and arguably chromium) are recognized as nutritionally essential by the Institute of Medicine. A handful of additional elements (boron, silicon, vanadium, nickel) have suggestive but not established dietary roles. Nothing in the recognized biochemistry approaches 102. Second, no laboratory technique used in food analysis — ICP-MS, ICP-OES, AAS, or neutron activation — produces a list of 92 distinct minerals in any food. ICP-MS can in principle detect any element above its limit-of-detection, but in routine seaweed analyses the panel that is actually reported is typically 15 to 30 elements, including the macrominerals, the essential trace minerals, and a handful of contaminants (cadmium, arsenic, lead, mercury, aluminum).

Sea moss does, like most marine algae, accumulate elements broadly from seawater because every element dissolved in the ocean is at least potentially present. But "potentially present at parts-per-trillion" is not the same as "a meaningful dietary source." The actual lab data, summarized below, paint a picture of a respectable but not extraordinary mineral food whose marketing has substantially outrun its evidence.

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What Sea Moss Actually Contains (USDA + Peer-Reviewed Data)

The USDA FoodData Central entry for "Seaweed, Irish moss, raw" (FDC ID 168455, derived from older USDA Standard Reference data) reports the per-100-gram nutrient profile shown below. These numbers are for the raw wet alga and need to be scaled down for typical sea-moss-gel serving sizes (a heaping tablespoon of prepared gel is roughly 30 grams wet, derived from about 2 to 4 grams of dry alga rehydrated to ten or more times its dry weight).

Per 100 g raw Chondrus crispus, USDA FoodData Central:

The peer-reviewed phycology literature adds a few elements that USDA does not directly tabulate — primarily sulfur (a structural component of the carrageenan polysaccharide that makes up roughly 60% of the dry weight), and chromium, molybdenum, and boron at trace levels. The bottom line is that a typical 30-gram (wet) tablespoon-sized serving of prepared sea moss gel delivers roughly:

This is a useful but not extraordinary mineral contribution — comparable on a per-serving basis to a small handful of pumpkin seeds, a serving of yogurt, or a small piece of dark leafy green. The headline mineral is iodine, by an order of magnitude. The headline contaminant is heavy metals, also by an order of magnitude.

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The Macrominerals: Potassium, Calcium, Magnesium, Sulfur

The four macrominerals delivered in meaningful amounts by sea moss are potassium, calcium, magnesium, and sulfur. None of these are unique to sea moss — all are abundantly available from ordinary whole foods at higher density per calorie — but sea moss does contribute usefully if it is one component of a varied diet.

Potassium is the dominant intracellular cation, required for nerve impulse transmission, muscle contraction (including cardiac), and blood pressure regulation. The adequate intake is 4,700 mg per day for adults, a level that fewer than 5% of Americans meet. Sea moss contains 1,000 to 3,000 mg per 100 g dry weight per most peer-reviewed phycology measurements, which translates to roughly 200 to 600 mg in a typical 30-gram (wet) tablespoon serving of gel — a non-trivial contribution but well below what a single banana (420 mg), avocado (700 mg), or cup of cooked spinach (840 mg) provides. The USDA database entry shows an anomalously low 63 mg per 100 g raw, which is likely an outdated or atypical sample — cross-reference with the peer-reviewed phycology literature before treating that number as authoritative.

Calcium at 72 mg per 100 g raw is modest by any standard — 100 grams of yogurt provides roughly 110 mg, a cup of fortified plant milk 300 mg, a handful of almonds 75 mg. The calcium in sea moss is present as soluble salts and as components of the cell wall; bioavailability has not been formally quantified but is presumed comparable to other plant sources (somewhat lower than dairy due to the presence of phytates and oxalates).

Magnesium at 144 mg per 100 g raw is sea moss's strongest macromineral claim — a typical serving provides roughly 40 to 50 mg, or about 10% of the daily requirement. This is comparable to a half-cup of cooked black beans (60 mg), a cup of brown rice (84 mg), or a small piece of dark chocolate (50 mg). Magnesium is required for over 300 enzymatic reactions including ATP production, DNA synthesis, neuromuscular transmission, and vasodilation; most American adults consume 200 to 300 mg per day against an RDA of 400 to 420 mg, so any additional plant-source magnesium has value. See the dedicated magnesium page for therapeutic dosing and clinical applications.

Sulfur is structurally abundant in sea moss because the dominant polysaccharide is carrageenan, a sulfated galactan whose sulfate groups (-SO3-) account for 25 to 35% of the polysaccharide's mass. Whether this sulfate translates to nutritionally useful sulfur is debated — the linkage is to the polysaccharide backbone and is largely indigestible to human enzymes, so most of the sulfur passes through to the colon where it is partially liberated by microbial sulfatases. Whether this contributes to host sulfur status (relevant to glutathione synthesis, glycosaminoglycan production, and methylation chemistry) or simply increases colonic hydrogen sulfide is not established.

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Trace Minerals: Iron, Zinc, Manganese, Copper, Selenium

The trace minerals in sea moss tell a similar story — respectable but not transformative content, with iron and zinc being the standout contributors and selenium being a notable disappointment given the "ocean-sourced superfood" framing.

Iron at 8.9 mg per 100 g raw is impressively high in absolute terms and is one of sea moss's genuine nutritional strengths — comparable per gram to red meat. A 30-gram serving delivers roughly 2.5 mg of iron, or about 14% of the daily requirement for premenopausal women. The form is non-heme iron (the form present in all plant sources), which has bioavailability of roughly 5 to 10% in the absence of facilitators and inhibitors — comparable to spinach but lower than heme iron from animal sources. Vitamin C taken at the same meal can roughly triple non-heme iron absorption; calcium, tannins from tea, and phytates inhibit it. For the broader iron-status conversation see the iron page.

Zinc at 1.95 mg per 100 g raw provides about 0.6 mg per typical serving, or 5 to 8% of the daily requirement. Not a primary zinc source but a useful contribution alongside other plant zinc sources (pumpkin seeds, hemp seeds, chickpeas). Zinc bioavailability from sea moss has not been formally tested but is presumed comparable to other plant sources (lower than red meat or oysters due to phytate competition).

Manganese at 0.37 mg per 100 g raw is a useful contribution to the 1.8 to 2.3 mg/day adequate intake — about 5% of daily needs per serving. Manganese is required for the antioxidant enzyme manganese-superoxide dismutase (MnSOD), bone formation, and carbohydrate metabolism. Manganese deficiency is rare but the mineral is generally underappreciated.

Copper at 0.149 mg per 100 g raw delivers about 0.045 mg per serving, or 5% of the 900 mcg RDA. Copper is required for ceruloplasmin, lysyl oxidase (collagen and elastin cross-linking), cytochrome c oxidase, and superoxide dismutase. The Morley Robbins copper-iron-mineral conversation places considerable emphasis on dietary copper from whole foods — see whole-food copper sources for that framework.

Selenium at 0.7 mcg per 100 g raw is the standout disappointment — sea moss is essentially not a selenium source despite the popular assumption that anything from the ocean must be selenium-rich. Marine fish and Brazil nuts dominate the dietary selenium landscape by several orders of magnitude. A single Brazil nut delivers 60 to 90 mcg of selenium; a serving of sea moss delivers 0.2 mcg. This matters specifically because selenium is the cofactor for the deiodinase enzymes that convert T4 to active T3 and for glutathione peroxidase, and sea moss is widely marketed for thyroid support — the iodine without the selenium is precisely the wrong nutritional pairing for the at-risk Hashimoto's population. See the selenium page.

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Sea Moss as an Electrolyte Source: Real Numbers

The four ionic species that together constitute "electrolytes" in physiological terms are sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+), with chloride (Cl-) as the dominant anion. The functional role of an electrolyte drink — whether commercial (Gatorade, Liquid IV, LMNT) or homemade — is to deliver ionic species that maintain extracellular fluid volume, cellular membrane potentials, neuromuscular function, and cardiac rhythm during exercise, illness, or fluid losses.

A typical 30-gram (wet) tablespoon of sea moss gel contributes, per the figures above:

For comparison, a packet of LMNT delivers 1,000 mg sodium, 200 mg potassium, and 60 mg magnesium per serving — engineered for athletes and low-carb dieters who need sodium-forward repletion. A single banana delivers 420 mg potassium. A cup of coconut water delivers about 250 mg potassium and 50 mg sodium. A serving of sea moss falls in the same general league as one of these on the potassium and magnesium axes but is essentially sodium-free.

The practical implication is that sea moss can function as a useful background source of potassium and magnesium — the two electrolytes most American adults are chronically short of — but it is not a substitute for proper electrolyte repletion in an athlete losing sweat sodium, a person with acute gastroenteritis losing volume to vomiting and diarrhea, or anyone on a low-carbohydrate diet experiencing the classic sodium-depletion symptoms (lightheadedness, fatigue, muscle cramps, headache). For those situations, a measured oral rehydration solution (the WHO/UNICEF ORS formula, or a commercial equivalent with both sodium and potassium) is the correct tool, not sea moss.

The marketing of sea moss as a "natural electrolyte drink" conflates two things — the general goodness of dietary potassium and magnesium with the specific physiological scenario where an engineered electrolyte solution is needed. Both can be true: sea moss is a worthwhile dietary contribution, and it is not the right intervention during acute fluid losses.

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The Heavy-Metal Problem: Cadmium, Arsenic, Lead, Aluminum

The same bioconcentration mechanism that makes sea moss a useful iodine and trace-mineral source also makes it a heavy-metal accumulator. Brown and red algae bind divalent metal cations to the carboxylate and sulfate groups in their cell-wall polysaccharides (alginates in brown algae, carrageenans in red algae) with high affinity, concentrating elements from ambient seawater by factors of 1,000 to 10,000. For nutritionally desirable elements like iron and zinc this is a feature. For cadmium, inorganic arsenic, lead, and aluminum it is a liability.

Cadmium is the most consistent contamination concern in commercial seaweed. The European Food Safety Authority (EFSA) Scientific Opinion on cadmium set a tolerable weekly intake of 2.5 mcg per kg body weight per week (about 25 mcg per day for a 70-kg adult). Reported cadmium content in commercial Chondrus crispus and Eucheuma cottonii samples typically ranges from 0.1 to 2.5 mg per kg dry weight. A 4-gram dry serving could deliver 0.4 to 10 mcg of cadmium — potentially 40% of the daily tolerable intake from a single serving of contaminated product. Daily consumption of high-cadmium product over years drives bioaccumulation in kidney cortex, where the metal's biological half-life is 10 to 30 years, and is implicated in chronic kidney disease and renal proximal tubular dysfunction.

Arsenic in seaweed exists in both inorganic (toxic) and organic (arsenobetaine, arsenosugars, generally non-toxic) forms. Total arsenic in red algae is typically 1 to 30 mg per kg dry weight; the inorganic fraction is usually less than 10% of the total but can be higher in some species and harvest regions. Inorganic arsenic is a recognized human carcinogen, associated with bladder, lung, and skin cancers at chronic doses. The EFSA-derived benchmark dose lower confidence limit for inorganic arsenic-associated cancer (BMDL01) is 0.3 to 8 mcg per kg body weight per day, so any chronic exposure source warrants scrutiny. For more detail see the arsenic toxin page.

Lead contamination is variable and primarily a function of harvest region — coastal areas near industrial discharges, mining runoff, or heavily-trafficked shipping lanes show measurable lead in seaweed crops. Reputable suppliers should test and disclose lead levels; the FDA action level for lead in candy intended for children is 0.1 ppm, and most quality-tested sea moss products report less than this in finished product.

Aluminum bioaccumulates in some seaweeds, with reported concentrations of 5 to 50 mg per kg dry weight. Aluminum has no known nutritional role and chronic exposure has been associated (with debate) with neurological and bone disease. Most sea moss products are not routinely tested for aluminum.

The 2020 Banach et al. paper in Food and Chemical Toxicology systematically reviewed heavy metal content across edible seaweeds and concluded that daily seaweed consumers in some Asian populations exceed the tolerable weekly intake for cadmium and inorganic arsenic from food sources, with seaweed being the dominant contributor. For Western consumers using sea moss daily as a supplement, the same calculation applies — chronic daily dosing without batch-specific heavy-metal testing creates a real, measurable bioaccumulation risk.

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Wildcrafted vs Pool-Cultivated Sourcing

Sea moss in commerce comes from two fundamentally different production methods that produce different mineral profiles, different contamination risks, and different ecological footprints.

Wildcrafted Atlantic Chondrus crispus is harvested from cold North Atlantic rocky coastal zones, primarily in Ireland, Canada (Prince Edward Island, Nova Scotia), Maine, and parts of northern France. The alga grows attached to rocks in the intertidal and shallow subtidal zones, and is harvested by rake or by hand-cutting at low tide. This is the "true Irish moss" of historical Irish cuisine (used as a thickening agent in flummeries and milk-based puddings). Mineral content is generally higher and more variable, iodine content is often substantial (the cold North Atlantic has higher iodide in seawater than tropical waters), heavy-metal contamination correlates with harvest-region industrial history.

Pool-cultivated Eucheuma cottonii (also marketed as Kappaphycus alvarezii) is grown in tropical and subtropical coastal farms, primarily in the Philippines, Indonesia, Tanzania (Zanzibar), and the Caribbean (St. Lucia, Jamaica). Production is done by tying seedling fragments to long lines anchored in shallow protected bays where the alga grows for 45 to 60 days before harvest. This warm-water alga is the dominant commercial source of the carrageenan used as a food additive globally (E407), and increasingly the dominant form of consumer sea moss product because its production scales easily. Iodine content is generally lower than Atlantic Chondrus crispus (50 to 200 mcg/g dry rather than 470 to 2,000), mineral profile is somewhat thinner, and heavy-metal contamination depends heavily on the specific farm location and water quality.

A third category — product marketed as "wildcrafted Caribbean sea moss" — is often a marketing claim rather than an accurate description. Most Caribbean sea moss in commerce is farm-cultivated Eucheuma cottonii; truly wild Caribbean sea moss is harvested in small quantities and commands a premium. Consumers should be skeptical of "wildcrafted" labeling without supporting traceability.

For the consumer trying to make an informed sourcing choice:

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Processing Methods and Bioavailability

The way sea moss is processed between harvest and consumption affects mineral content, bioavailability, and contamination risk in several ways.

Sun-drying versus oven-drying — traditional Atlantic harvest involves spreading the freshly cut alga on rocks or racks in the sun for several days, with periodic turning. Sun-dried product retains pigments and tends to be greenish-gold to purple. Industrial product is sometimes oven-dried at higher temperatures, which can degrade some heat-sensitive compounds (vitamin C, some phenolics) but does not significantly affect mineral content.

Bleaching — some industrial product is treated with sodium hypochlorite or hydrogen peroxide to produce the pale yellow-white "golden sea moss" appearance that some consumers prefer. Bleaching denatures some surface organic chemistry and can introduce residual chlorine. Look for unbleached, naturally-colored product (which will be greenish-gold, purple, or brown depending on species and growing conditions, not uniform pale yellow).

Salting — most commercial sea moss arrives heavily salted, both as a preservation strategy and as a by-product of harvest from seawater. Salt should be rinsed off thoroughly (multiple changes of fresh water over 12 to 24 hours) before preparing gel. Inadequate rinsing leaves the consumer ingesting substantial sodium with each serving — defeating the "low sodium" nutritional profile.

Soaking and rinsing — the standard sea moss gel preparation soaks the dried alga in cool water for 12 to 24 hours, then rinses and blends. The soaking step rehydrates the carrageenan polysaccharide (which expands roughly tenfold in volume) and leaches some surface contaminants. Some iodine and water-soluble minerals are also leached into the soaking water — this is one reason iodine content varies between batches of the same dried product.

Heat preparation — some consumers boil sea moss before blending; others prefer cold preparation. Boiling further reduces iodine content (volatile losses) and can degrade some heat-sensitive bioactive compounds. Cold preparation preserves more of the nutritional profile but does not eliminate microbial contamination, which is a concern for raw sea moss from warm coastal harvest waters where Vibrio species and other marine pathogens may be present.

Capsule and powder products — finely-ground dried sea moss in capsules concentrates the mineral content (and the heavy-metal content) per serving. A standard 500 mg capsule delivers about 12% of a tablespoon-of-gel mineral load but at the same heavy-metal concentration. For consumers using capsules daily, the heavy-metal cumulative exposure can be significant. Third-party testing is more important, not less, for capsule formats.

Bioavailability of the mineral content is generally presumed to be moderate — comparable to other plant sources — but has not been formally quantified in clinical studies. The carrageenan matrix may bind some minerals and reduce their absorption, particularly divalent cations like calcium, iron, and zinc. Co-ingestion with vitamin C (for non-heme iron) and avoidance of co-ingestion with calcium supplements or tea (for iron and zinc) follows the same general rules as for other plant mineral sources.

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Comparison to Whole-Food Mineral Sources

Set against ordinary whole foods on a per-serving basis, sea moss is a respectable contributor but not a category leader for any single mineral except iodine. The table-style comparison below shows typical contributions of one serving of sea moss against more familiar food sources:

The honest summary: sea moss is a useful supplemental food for daily mineral intake, particularly meaningful for plant-based eaters as an iron and trace-mineral source, with iodine being its single distinctive nutritional contribution. The "92 minerals" marketing framing significantly overstates this. A varied diet of whole foods including dark leafy greens, legumes, nuts and seeds, dairy or fortified alternatives, and a sodium-iodized salt or moderate seafood intake delivers the same minerals at higher density per serving and without the heavy-metal accumulation concern.

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Practical Sourcing and Testing Guidance

For consumers who choose to include sea moss in their diet on a regular basis, the practical sourcing and testing steps that meaningfully reduce risk are:

  1. Buy whole dried sea moss, not capsules. Whole dried product is verifiable visually for species, harvest condition, and bleaching, and the rinsing step before gel preparation reduces residual salt and surface contamination. Capsules concentrate any contamination per serving.
  2. Require a Certificate of Analysis (COA). A reputable supplier will publish or provide on request a third-party laboratory analysis including cadmium, inorganic arsenic, lead, mercury, and ideally aluminum. Cadmium below 0.5 mg/kg dry weight, inorganic arsenic below 0.5 mg/kg, and lead below 0.1 mg/kg are reasonable thresholds for daily-consumption product.
  3. Iodine content disclosure. The supplier should publish iodine content per gram of dry weight or per typical serving. Variability of 100-fold between batches makes this disclosure essential for anyone with thyroid concerns — see the Thyroid and Iodine page for the full framework.
  4. Rinse thoroughly before preparation. Multiple changes of cool fresh water over 12 to 24 hours, until the soaking water runs clear. This reduces residual sea salt and surface contamination.
  5. Rotate suppliers and harvest regions. Daily long-term consumption from a single source compounds any one supplier's specific contamination profile. Rotating across two or three vetted sources reduces this risk.
  6. Limit dose. One to two tablespoons of prepared gel per day is the typical recommendation; daily intake above this raises both iodine and heavy-metal exposure proportionally.
  7. Periodic biomarker checks for daily users. Annual urinary iodine concentration and, for users consuming sea moss daily for years, periodic kidney function tests (eGFR, urine albumin-to-creatinine ratio) make sense to monitor for any cumulative cadmium-driven proximal tubular dysfunction.
  8. Special populations: avoid or use minimal doses. Pregnant and lactating women, children under 12, patients with chronic kidney disease, and patients with autoimmune thyroid disease should default to no sea moss or to very low conservative doses with clinical supervision.

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Key Research Papers

  1. Circuncisão AR et al. (2018). Minerals from macroalgae origin: health benefits and risks for consumers. Marine Drugs. — PubMed
  2. Banach JL et al. (2020). Food safety hazards in the European seaweed chain. Comprehensive Reviews in Food Science and Food Safety. — PubMed
  3. Roleda MY et al. (2019). Variations in polyphenol and heavy metal contents of wild-harvested and cultivated seaweed bulk biomass: health risk assessment and implication for food applications. Food Control. — PubMed
  4. Almela C et al. (2006). Total arsenic, inorganic arsenic, lead and cadmium contents in edible dried seaweed in Spain. Food and Chemical Toxicology. — PubMed
  5. Mac Monagail M et al. (2017). Sustainable harvesting of wild seaweed resources. European Journal of Phycology. — PubMed
  6. Holdt SL, Kraan S (2011). Bioactive compounds in seaweed: functional food applications and legislation. Journal of Applied Phycology. — PubMed
  7. Teas J et al. (2004). Variability of iodine content in common commercially available edible seaweeds. Thyroid. — PubMed
  8. Hwang YO et al. (2010). Total arsenic, mercury, lead, and cadmium contents in edible dried seaweed in Korea. Food Additives & Contaminants: Part B. — PubMed
  9. Desideri D et al. (2016). Essential and toxic elements in seaweeds for human consumption. Journal of Toxicology and Environmental Health, Part A. — PubMed
  10. European Food Safety Authority (EFSA) (2009). Scientific Opinion on cadmium in food. EFSA Journal. — PubMed
  11. EFSA Panel on Contaminants in the Food Chain (2009). Scientific Opinion on arsenic in food. EFSA Journal. — PubMed
  12. Pereira L (2011). A review of the nutrient composition of selected edible seaweeds. Seaweed: Ecology, Nutrient Composition and Medicinal Uses. — PubMed
  13. MacArtain P et al. (2007). Nutritional value of edible seaweeds. Nutrition Reviews. — PubMed
  14. Pañis C et al. (2020). Selenium, copper, zinc and other trace elements in seaweeds: bioavailability and health implications. Critical Reviews in Food Science and Nutrition. — PubMed

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