Sea Kelp 2520mg: 500μg Natural Iodine for Normal Thyroid Function
Sea kelp is the common name for large brown seaweeds that grow in shallow coastal waters; the species in our tablets is Ascophyllum nodosum, the knotted wrack of North Atlantic shores. Kelp is valued mainly for its iodine, and iodine contributes to the normal production of thyroid hormones and normal thyroid function[2]. This guide covers what kelp is, the five benefits UK law authorises for iodine and how much iodine you get in each of our tablets.
Like other brown seaweeds, kelp takes up minerals from seawater and contains polysaccharides such as alginate and fucoidan; the nutrient our label declares is iodine, 500 micrograms (μg) per tablet[3]. A 2021 analysis of commercially available kelp and seaweed products found that the iodine content of supplements ranged from 5 to 5,600μg per daily dose, which is why a standardised extract with a declared iodine figure matters[4].
SEA KELP 2520MG – 180 TABLETS
£7.99 · 180 servings · 2520mg / Tablet
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Iodine and the Thyroid: What Sea Kelp Provides
The thyroid gland uses iodine to make the hormones thyroxine (T4) and triiodothyronine (T3). The NHS says adults need 140μg of iodine a day, that good food sources are cows’ milk and dairy products, eggs, sea fish and shellfish, and that people following a strict vegan diet who eat none of these may want to consider foods fortified with iodine or an iodine supplement. Kelp is a plant-based source of iodine, and the GB Nutrition and Health Claims Register lists that iodine contributes to the normal production of thyroid hormones and normal thyroid function.
Every health claim on the Great Britain register passed a scientific review: independent scientists examined the research and the evidence behind it before it was authorised. The law itself says that health claims shall be “based on and substantiated by generally accepted scientific evidence” (Regulation (EC) No 1924/2006, Article 6).
Our Sea Kelp tablet provides 500μg of iodine, which is 333% of the nutrient reference value (NRV) of 150μg[3]. Explore our algae range for kelp, bladderwrack, sea moss, spirulina and chlorella.
Iodine Claims in the GB Register: The Exact Wording
Our tablet is a source of iodine, a nutrient with five authorised health claims in the register: iodine contributes to the normal production of thyroid hormones and normal thyroid function; iodine contributes to normal cognitive function; iodine contributes to normal energy-yielding metabolism; iodine contributes to normal functioning of the nervous system; and iodine contributes to the maintenance of normal skin[2].
“Iodine helps make thyroid hormones, which help keep cells and the metabolic rate (the speed at which chemical reactions take place in the body) healthy.”
Vitamins and minerals: Iodine, nhs.uk
What Our Sea Kelp Tablet Contains
The figures below come from the product label and its nutritional information table.
Sea Kelp 2520mg: each tablet contains the equivalent of 2,520mg of sea kelp from a 40:1 extract standardised to 0.8% iodine, providing 500μg of naturally occurring iodine (333% NRV). Iodine contributes to the normal production of thyroid hormones and normal thyroid function.
Which Sea Kelp Is Right for You?
If you want a plant-based source of iodine: one of our vegan tablets a day gives you 500μg of iodine (333% NRV) from Ascophyllum nodosum[3].
If you prefer a capsule: our Bladderwrack 500mg capsules (90 capsules, £8.99) provide the same 500μg of iodine per capsule from Fucus vesiculosus; with either product the daily dose is one.
If you read labels — three lines tell you what you’re buying: the iodine per tablet with its %NRV (500μg, 333% on ours), the standardisation (ours is a 40:1 extract standardised to 0.8% iodine, so every tablet provides the same figure), and the seaweed species (Ascophyllum nodosum).
Our Sea Kelp 2520mg Tablets: The Facts
Our Sea Kelp 2520mg – 180 Tablets provide the equivalent of 2,520mg of Ascophyllum nodosum per tablet from a 40:1 extract standardised to 0.8% iodine, which is 500μg of iodine (333% NRV). The suggested use is one tablet daily with water; the pouch of 180 vegan tablets is a six-month supply and costs £7.99 at the time of writing[3]. The other ingredients are microcrystalline cellulose, a hypromellose coating, croscarmellose sodium and magnesium stearate, and the tablets are made in the EU. If you would rather take a capsule, our Bladderwrack 500mg – 90 Capsules (£8.99) also provide 500μg of iodine per capsule, from Fucus vesiculosus.
A PLANT-BASED SOURCE OF IODINE
Our Sea Kelp 2520mg provides 500μg of iodine per tablet (333% NRV). Iodine contributes to the normal production of thyroid hormones and normal thyroid function.
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Sea Kelp FAQs
1. What does iodine do, according to the NHS and the register?
The NHS says iodine helps make thyroid hormones, which help keep cells and the metabolic rate healthy, and that adults need 140μg a day. The authorised claims are that iodine contributes to the normal production of thyroid hormones and normal thyroid function, to normal cognitive function, to normal energy-yielding metabolism, to normal functioning of the nervous system and to the maintenance of normal skin. Sea kelp is a plant-based source of iodine.
2. How much Sea Kelp should I take daily?
One tablet a day with water, as the label directs[3]. Each tablet provides 500μg of iodine, and the NHS says 0.5mg or less a day of iodine from supplements is unlikely to cause any harm[1]. If you have a thyroid condition, take thyroid medication, or are pregnant or breastfeeding, speak to your GP or pharmacist before taking kelp or any iodine supplement.
3. Why does the iodine content of kelp products vary so much?
Seaweeds take up iodine from seawater, and the amount depends on the species, the season and where it was harvested. The 2021 analysis of kelp and seaweed products found iodine ranging from 5 to 5,600μg per daily dose in supplements[4]. A standardised extract with the iodine figure declared on the label, as on our tablets, removes that guesswork.
Sea kelp (Ascophyllum nodosum) is a brown seaweed and a natural source of iodine. Iodine contributes to the normal production of thyroid hormones and normal thyroid function, to normal cognitive function, to normal energy-yielding metabolism, to normal functioning of the nervous system and to the maintenance of normal skin. Our Sea Kelp 2520mg gives you 500μg of iodine (333% NRV) in one vegan tablet a day, and a pouch of 180 tablets costs £7.99, enough for six months[3].
References
[1] NHS. Vitamins and minerals: Iodine (140μg a day for adults; food sources; 0.5mg or less a day from supplements unlikely to cause harm). View Guide
[2] Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register, GOV.UK (accessed 2026-09-11; iodine claims). View Register
[3] Alpha01. Sea Kelp 2520mg – 180 Tablets: nutritional information, ingredients and price (accessed 2026-09-11). View Product
[4] Aakre, I., et al. (2021). Commercially available kelp and seaweed products – valuable iodine source or risk of excess intake? Food & Nutrition Research, 65, 7584. View Study
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