Natural Iodine: Commonly deficient hormone and metabolism orchestrator

Supplementation in context

A single supplement will never be a magic bullet for our health as the human body requires a synergy of multiple nutriments (50 Essential bioavailable nutrients). These nutrients are required  in individually quantities determined by our genetics and our lifestyle conditions.  Supplements should always play a secondary supportive role in optimising health. A wholefoods diet, regular exercise, appropriate rest & optimal sleep should be our main focuses. Certain supplements are recommended for probable modern day nutrient deficiencies (a blood test will testify this) and increased nutrient demands when training. Typical modern lifestyles of high stress, high environmental pollution and processed nutrient deprived foods increase our needs for supplementation. Supplements are not compensators for an enduring poor diet.


Iodine is a trace mineral that naturally occurs as a salt (iodide); it prevents hypothyroidism (slow metabolism) and hyperthyroidism (hyperactivity). A healthy adult will have around 15-20g of iodine within their body found in every cell (50 mg of iodine in the thyroid, 20% in the skin and 32% in muscles).

Thyroid stimulating hormone (TSH) secreted by the pituitary gland controls thyroid hormone secretion and therefore Iodine thyroid uptake.

Iodine is 1 of the 3 most common nutritional deficiencies in developed societies along with magnesium (see my blog on green smoothies) and vitamin D (get your sunrise or sundown sunlight exposure April to September). Iodine deficiency will cause disease and increased cancer susceptibility.

Hypothyroidism (iodine deficiency) symptoms:

  • Dry mouth – insufficient saliva production
  • Dry skin – reduced sweating (3-4 week supplementation will correct this)
  • Lower brain IQ/alertness
  • Increased muscle pain, nodules, scar tissue, fibrosis and fibromyalgia
  • Sluggishness/tiredness
  • Difficulty losing weight
  • Hair loss, constipation & increased cold sensitivity
  • A goiter, an enlarged thyroid – the body attempting to capture more iodine
  • A lack of tyrosine, iodine, zinc or selenium can reduce thyroxine levels
  • Allergies/ autoimmune disorders can reduce thyroid activity

To test for a deficiency seek your healthcare provider and ask for a urinary iodine test:

Iodine urine concentrations
Normal Iodine excreted levels100-199mcg/L
Severe deficiency<20mcg/L

Why Iodine deficiency is common:

  • Iodine antagonist’s – Bromine, fluorine & chlorine consumption – these halogens displace iodine uptake blocking iodine cell receptors. Found in baked goods, plastics, soft drinks, some medications, pesticides and some tap water.
  • Reduced consumption of iodine-rich foods e.g. iodised salt, sea vegetables, eggs and sea foods
  • Soil mineral depletion – the exhaustion of soil minerals through mass production agricultural methods with insufficient replenishment. Especially in mountainous and areas of freshwater flooding
  • Lack of fortification in the food/agricultural industry
  • High Stress, stimulant consumption and an estrogen hormone dominance increase iodine demand

Hyperthyroidism symptoms:

  • Over-activity
  • Loss of weight
  • Nervousness

Too much long-term iodine consumption leads to suppressed thyroid function and subclinical hypothyroidism symptoms. However the average Japanese diet contains around 5g of seaweed per day, iodine in the range of 1,000-3,000mcg.

Iodine Benefits:

  • Key constituent of thyroid hormones
  • Orchestrates  energy metabolism and body weight, protein synthesis, enzymes, optimises immune function, fertility, hormone regulation (estrogen metabolism), increases cold tolerance, bone, brain and hair health
  • Child brain development
  • Anti-bacterial, anti-parasitic, anti-viral and anti-cancer properties (Increase apoptosis – cancer cell death)

Practical Supplement guidelines:

Conditional contextDosage
Average adult150mcg/day
Adult upper limit1100mcg/day

Wholefood sources:

Seaweed (highly variable content and potentially contaminated, seek reputable sources), seafood, Himalaya crystal salt, cranberries, raw dairy, eggs, iodised salt & breast milk

1g seaweed = 16-2984mcg

85g cod = 99mcg

1 cup plain yoghurt = 75mcg

2/3rds teaspoon or 1.5g Ionised salt = 71mcg

85g shrimp = 35mcg

1 Large egg = 24 mcg

Daily Seaweed supplementation (an iodine safeguard):

  • Lowest source of iodine come from Nori. Nori is never rich enough to pose a significant health risk. Consume 2 sheets/day = 150 mcg
  • Dulse/Wakame is moderate, excessive consumption of over 10-20g daily could cause issues. Consume ½ teaspoon/day = 150mcg
  • Arame & kelp (Kombu) are highest iodine sources of up to 2,660 mcg per g posing a significant risk for iodine toxicity. Take ¼ teaspoon/day

Boiling seaweed in water for 15-30 minutes appears to be sufficient in reducing iodine content

Co-ingestion of seaweed products with goitrogen containing foods  (foods that interfere with iodine uptake) may provide a possible protection against high iodine intakes. E.g. soy, cassava, cruciferous veg (broccoli, cabbage, cauliflower, kale etc)

 Here is the seaweed food supplements I recommend form local independent health food shop Greens

How to incorporate seaweed into your daily diet:

– Stirred into a smoothie or fresh squeezed juice

– Mixed into a salad dressing

– Blended into dips

– Add to stocks and soups

– Use ground seaweeds as a salt substitute and/or combine with spices

Ways to avoid biological iodine displacers:

1) Avoid contact with plastics. For food and drinks use glass and ceramic containers

2) Eat organic, thoroughly wash produce to minimise pesticide ingestion.

3) Looked for no bromine or bromine free baked goods (this is banned in the uk)

4) Avoid drinking soda & tap water

5) Install a home water purification system to extract fluorine and chlorine

6) Seek natural personal care products

Ways to increase fluorine/bromine excretion: high-dose iodine consumption, high-dose vitamin c consumption (see my other blog on the benefits of vitamin C), unrefined sea salt, Epsom salt baths & sweating (saunas/cardio).