Does Spirulina Contain Iodine?

Written by: Pard Bharaj



Time to read 5 min

Image of Pard, the Author

Author: Pard Bharaj

I am a dedicated researcher with nearly a decade of experience in investigating health best practices. 

Disclaimer: The information provided in this article is for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition or before making any changes to your diet or lifestyle, especially if you have existing health conditions.


Our regular readers will be well aware that Spirulina, a blue-green algae, has gained significant popularity as one of the world's most nutritious superfoods. It is very rich in vitamins, and minerals, and has been a well researched algae that can offer numerous health benefits.

This article will discuss if spirulina contains iodine, explore the health benefits of iodine, and discuss the implications of consuming spirulina for those mindful of their iodine intake.

The Importance of Iodine in Diet:

Iodine is a crucial mineral required for the synthesis of thyroid hormones, which regulate metabolic processes, growth, and development in the human body. Adequate iodine levels are essential for maintaining healthy thyroid function and preventing conditions such as goitre and hypothyroidism.

The benefits of iodine extend beyond thyroid health. It supports proper brain development during pregnancy and infancy, enhances cognitive function, and boosts the immune system. Iodine also plays a role in maintaining skin health and ensuring the proper functioning of cells and organs.

Iodine Recommended Daily Allowance: 

The recommended daily intake of iodine varies by age and life stage. The NHS mentioned that for adults, the recommended amount is about 150 micrograms per day. Pregnant and breastfeeding women require higher amounts, according to the National Institutes of Health, approximately 220 to 290 micrograms per day is recommended to support the increased needs of their developing baby.

Does Spirulina Contain Iodine? 

Spirulina does contain iodine, but the levels can vary significantly depending on its source and cultivation conditions. Scientific studies and nutritional analyses have shown that the iodine content in spirulina is generally low compared to other iodine-rich foods.

( quote that ‚Äúon average,¬†a gram of spirulina contains about 5 micrograms of iodine.¬†While this is relatively low compared to other iodine-rich foods, it can still contribute to your daily iodine intake if consumed regularly‚ÄĚ.¬†

When compared to other iodine-rich foods such as seaweed, dairy products, and iodized salt, spirulina generally has much lower iodine levels. For instance, seaweeds like nori can contain thousands of 23.2 micrograms of iodine per 1 gram, making them a far more concentrated source of this essential mineral. Therefore, while spirulina can contribute to overall iodine intake, it is not considered a primary source of iodine in the diet.

Iodine in Natural Foods Comparison Table:

Does Spirulina Contain Iodine - Food Comparison Table

Health Implications of Iodine in Spirulina:

While spirulina provides some iodine, there are important considerations for individuals with iodine sensitivities or thyroid conditions. 

Here are the key points: 

  1. Iodine Sensitivities:

    • Some individuals may have sensitivities or allergies to iodine. Even small amounts of iodine can trigger allergic reactions, such as skin rashes, stomach upset, or more severe symptoms like anaphylaxis in rare cases.

  1. Thyroid Conditions:

    • Hypothyroidism:¬†Individuals with hypothyroidism need to carefully manage their iodine intake. Excess iodine can potentially worsen the condition or interfere with thyroid hormone medications.

    • Hyperthyroidism:¬†For those with hyperthyroidism, excessive iodine intake can exacerbate symptoms. It‚Äôs important to monitor iodine intake to prevent over-stimulation of the thyroid gland.

    • Autoimmune Thyroid Disease:¬†Conditions such as Hashimoto's thyroiditis can be sensitive to iodine levels. Both deficiency and excess iodine can negatively impact thyroid function, thus balancing intake is crucial.

3.  Practical Advice: 

    • Consultation with Healthcare Providers:¬†Individuals with thyroid conditions or iodine sensitivities should consult healthcare providers before adding spirulina or any new supplement to their diet. This ensures that their specific health needs and dietary restrictions are considered.¬†
    • Check Packaging:¬†It's important to note that the iodine content in spirulina can vary depending on the growing conditions and the specific product. Always check the nutrition label if you are consuming spirulina specifically for its iodine content (My Nutrigene).
    • Gradual Introduction:¬†Introducing spirulina gradually and observing any changes in symptoms can help in determining personal tolerance levels.¬†

Conclusion: Does Spirulina Contain Iodine?

In summary, spirulina is a nutrient-dense superfood that contains a variety of essential vitamins and minerals, including iodine in small amounts. While the iodine content in spirulina is relatively low compared to other iodine-rich foods, it can still contribute to daily iodine intake, particularly in a 5-gram serving.

However, individuals with iodine sensitivities or thyroid conditions  need to approach spirulina consumption cautiously. Consulting with healthcare providers and monitoring iodine levels are crucial steps to ensure it fits well within their dietary needs and health goals.

Overall, spirulina offers numerous health benefits, and its modest iodine content can be a useful addition to a balanced diet. Yet, awareness and understanding of its implications for iodine intake are vital for those with specific health considerations.

References and Further Reading:

1. Dietary exposure to heavy metals and iodine intake via consumption of seaweeds and halophytes in the European population:

Summary: The study found that seaweeds contribute to dietary iodine intake, with varying levels depending on the type of seaweed. While brown algae like Kombu showed the highest iodine levels, spirulina also contributed to overall iodine intake in the diet.

Authors : European Food Safety Authority (EFSA), Bruno Dujardin, Rita Ferreira de Sousa, and Jose √Āngel G√≥mez Ruiz.

2. Accumulation of trace elements by biological matrice of Spirulina platensis:

Summary:¬†This study demonstrates that Spirulina can be enriched with essential trace elements, including iodine, through cultivation in nutrient mediums containing these elements. It establishes that Spirulina retains its natural beneficial properties and protein composition while accumulating iodine, making it suitable for developing pharmaceutical supplements containing precise doses of iodine (100-200 ¬Ķg per 0.5 g).

Authors: Marina V. Frontasyeva, Sergey S. Pavlov, Liguri Mosulishvili, Elena Kirkesali, Eteri Ginturi, and Nana Kuchava.

3. Iodine

Summary: The NHS article states that iodine helps make thyroid hormones, which keep cells and the metabolic rate healthy. Good sources of iodine include cow's milk, dairy products, eggs, sea fish, and shellfish. Adults need 140 micrograms of iodine per day. Taking high doses of iodine for long periods can affect thyroid function, leading to symptoms like weight gain.

4. Iodine - Fact Sheet for Health Professionals:

Summary: The NIH fact sheet explains that iodine is essential for thyroid hormone production, which regulates metabolism and development. Seaweed, fish, dairy, and eggs are good sources. Recommended daily intake for adults is 150 micrograms. Excessive iodine can lead to thyroid dysfunction. 

5. Spirulina and Iodine:

The Livestrong article explains that spirulina contains varying levels of iodine, which supports thyroid function. However, the iodine content in algae can exceed safe limits, posing risks like thyroid cancer and hyperthyroidism. Contamination with toxic substances is also a concern.

Frequently Asked Questions:

How much iodine is in a serving of spirulina?

A 5-gram serving of spirulina contains approximately 25 micrograms of iodine.

Can spirulina help with iodine deficiency?

  • While spirulina can contribute to daily iodine intake, it is not a primary source of iodine. Foods like seaweed have much higher iodine content.

How consistent is the iodine content in spirulina?

The iodine content in spirulina can vary depending on its source and cultivation conditions.

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