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Best Dietary Sources of Iodine

The trace mineral iodine is naturally present in a number of foods, and as your body cannot make its own iodine, you must obtain the needed iodine from your diet. Some of the best dietary sources of iodine include seaweed (such as kelp), dairy products, eggs, watercress, ocean fish, and foods that contain iodized salt. Sufficient levels of iodine are particularly important for the thyroid gland which uses iodine to produce thyroid hormone. If the thyroid gland does not get the iodine it needs, it may swell and cause the neck or larynx swell as well. This enlargement of the thyroid gland is known as goiter or goitre (Latin: struma, gutteria).

Other possible consequences of not consuming enough iodine rich foods (and the resulting low levels of thyroid hormone) include the inability to ovulate (anovulation) and infertility in women and an autoimmune disease of the thyroid. Some experts believe that iodine deficiency may also increase the risk of certain cancers such as thyroid, prostate, breast, endometrial and ovarian cancer.

Iodine deficiency during pregnancy is also a health concern as it can lead to high blood pressure for the mother. Insufficient iodine levels during pregnancy may also cause the baby to become mentally retarded. In the most extreme cases, congenital iodine deficiency may lead to cretinism, a condition characterized by severely stunted physical and mental growth.

If you suspect you may not be getting enough iodine, try adding some of the following foods to your diet — they are considered some of best dietary sources of iodine.

Kelp (and Other Seaweed)

Packed with a slew of health promoting nutrients, sea kelp (known as kombu in Japan) has earned a reputation as a "super food". Iodine is one of the important nutrients abundant in kelp. In fact, sea kelp or kombu is considered the best natural source of iodine in the world! So how much iodine does kelp contain? Most kelp or kombu has around 2500 mcg/gm, but some concentrated kelp granules may provide more than 8000 mcg/gm. If you're keen on buying organic kombu, check out the offer and reviews from Amazon here (if you live in the UK, click here).

The amount of iodine in other seaweeds is much lower. For example, hijiki seaweed provides about 629 mcg/gm, dulse 72 mcg/gm, wakame 32 mcg/gm and nori less than 20 mcg/gm.

Notice: Due to the extremely high concentration of iodine in kelp, it is advisable to consume it only in moderation as consuming too much iodine can cause some side effects.

Dairy Products

Iodine levels in milk vary significantly depending on what the cows producing the milk have been fed. Iodine content of milk also varies seasonally, with winter milk typically containing much higher levels of iodine than summer milk. Overall, the average amount of iodine in a cup of US (cow's) milk has been estimated to be somewhere between 58 and 116 mcg. Sheep's and goat's milk typically contain even higher levels. The iodine content of cheese, yoghurt, ice cream and other dairy products depends on the iodine levels of the milk they were made from and the type of the dairy product. Mozzarella cheese is considered a particularly rich source of iodine.


Watercress sprigs are often used on the side of a plate as a decorative garnish, but they can do much more than that. Watercress — one of the oldest known leaf vegetables consumed by human beings — is overflowing with health promoting nutrients such as beta-carotene, vitamin C, B vitamins, vitamin K, calcium, potassium, magnesium and, you guessed it, iodine. In fact, watercress is one of the best plant based sources of iodine and an important source of iodine for those following a vegan diet.

Eggs are often recommended for people deficient in iodine.


Eggs are often recommended for people who are advised to increase their iodine consumption, but how much iodine do eggs actually contain? The iodine content of eggs depends largely on how much iodine the feed of the hen that produced the eggs contained. In most cases, the iodine content of eggs is estimated to be somewhere between 13 and 70 mcg per one large eggs (50 grams). However, eggs of hen that have been fed a iodine rich diet may contain up to 200 mcg per egg. A fantastic way to benefit from egg iodine is to enjoy a portion of shrimp omelet which pairs eggs with another good source of iodine: the shrimp.

Foods That Contain Iodized Salt

Last but not least: iodized salt and foods that have been prepared with iodized salt can help our bodies' reach their iodine requirements. The practice of adding iodine to salt is promoted by WHO and other health organizations which have helped many countries set up national salt iodination programs. Salt has been chosen as a primary medium to battle iodine deficiency because it is consumed widely and because the cost of iodizing salt is extremely low (only about USD 0.05 per person per year). UNICEF estimates that 66% of households around the world have today access to iodized salt.

Related Content on This Site

  • Guide to Optimal Diet for Losing Weight. Lack of iodine in diet can result in sluggish thyroid activity which in turn can lead to weight gain or hinder weight loss. To learn all about the nutritional approach to weight loss, head to our online guide dedicated to the topic (link above).
  • Cellulite-Busting Diet, Foods and Recipes. In addition to fighting fat accumulation, iodine is thought to drain toxins such as heavy metals and synthetic molecules that may contribute to the appearance of cellulite. But there are many other dietary factors that can also contribute to the appearance of cellulite...
  • Side Effects of Too Much Iodine. As with many things in life, too much of a good thing can be bad for your health.