Iodine Supplements Vs Iodized Salt

Is the use of iodized salt enough to provide our bodies with the iodide it needs for optimal health or must we use an iodine supplement?

Let’s look at a little history and some basic chemistry.

Morton added iodide to their salt in 1924 to prevent an epidemic of enlarged thyroid glands (goiter) due to an iodide deficiency. Even though the result of including iodide in salt was successful science has yet to establish what amount of iodide human beings require for optimal health. Our MDR (minimum daily requirement) of 150 mcg is enough to prevent goiter and cretinism but not nearly enough to maximize thyroid hormone production or to protect us from other disease conditions related to iodine and iodide deficiencies.

Many studies (WHO & National Health and Nutrition Examination Survey) have shown that the general population of both the U.S. and worldwide are suffering from an insufficiency of these two essential trace elements. So the first question is can we rely on iodized salt to provide us with our daily needs for maximum health?

Iodized Salt

A teaspoon of iodized salt contains the following:

  • 2,300 mg of sodium (Our U.S. Department of Health and Human Sciences recommends that a healthy adult should not consume more than 2,300 mg of sodium. If they have high blood pressure, kidney disease, diabetes, are black, or if they are middle-aged or older they should not consume more than 1,500 mg. The ‘Surgeon General’s Report on Health Promotion and Disease Prevention’ of 1979 even condemned salt.
  • 2,700 mg of chloride
  • 300 mcg of iodide (0.3 mg)

From this information and taking into consideration our intake of salt added to prepared and restaurant foods iodized salt may not be the best and healthiest source of iodide.

Iodine & Iodide

The next logical question then is how much of these two trace elements do we require for health, not just to sustain life, but for vital health.

There’s a general consensus about vitamin and mineral requirements yet with iodine and iodide there’s a huge gap between physicians when considering a safe and effective dose. And both sides have very convincing research to support their point of view.

The conservatives believe that all the nutrients we need can be found in our food. This theory may have been true 60 years ago but our consumption of foods grown in nutrient depleted soils and manufactured foods has greatly reduced the essential nutrients we require. The conservative view also does not take into account people’s reluctance to use table salt.

Then there is the other extreme, physicians prescribing upwards of 50 mg of iodine and iodide per day. That’s 50,000 mcg compared with 150 mcg, 300 times the MDR. There may be some initial benefits to flooding the body with this much iodine and iodide but taken long-term there will be consequences.

Words of Caution

I used to be one of those high-dose prescribers until I repeated lab tests focusing on thyroid hormones. I was horrified by the results. I immediately stopped prescribing iodine and iodide and dove into the research myself.

The endocrine system’s reaction to high doses is a little too deep for this article but the primary result of high dosing is inflammation of the thyroid and over years the increased risk of a condition called Hashimoto’s.

One patient, before starting her on high-dose iodine and iodide, tested negative for Hashimoto’s but within 6 months her Hashimoto’s test turned positive.


I was surprised to find so much research on these two trace elements coming up with over 100 articles on their use in the prevention and treatment of numerous diseases.

Some of the research indicated a safe and effective dose while many articles agreed that people around the world, and not in just the less developed countries, are not getting anywhere near what they require.

Several articles pointed to between 3 and 6 mg a day as being safe. I tend to stand on the conservative side, recommending 3mg of iodine and iodide per day. This moderate dose slowly saturates the tissues and because it’s not the ‘flood-the-system’ high-dose approach the body will easily excrete what it does not need.

Which Iodine Supplement?

In products from the sea nature provides the combination of both iodine and iodide. With supplements you’ll find the ingredient is often only iodine. It will also be the elemental form and not made from food.

This means that most iodine supplements do not include iodide which is absolutely necessary for our thyroid to make its hormones. So to me supplements with iodine alone are out.

Iodine and Iodide Supplements

The most popular combination supplements (Iodoral & IodinePlus-2) fall into the category of the high-dose, usually 12.5 mg (12,500 mcg), and I recommend avoiding them even if your physician is doing lab tests. You can’t predict when you’ll reach that saturation threshold and start having thyroid inflammation.

Kelp Tablets

Kelp contains both iodine and iodide. There have been a number of survey studies showing how the cultures consuming higher amounts of seafood and sea vegetation have a much lower incidence of various illnesses including cancer. Yet these studies are from the 60’s and 70’s.

In the last 40 to 50 years our oceans have become our industrial waste sewage system with kelp, chlorella, plankton and reef life our only means of preserving the purity of our waters.

I recently approached a very large and well-known herbal supplement manufacturing company (Gaia Herbs) to have them formulate a kelp concentrate to deliver 3 mg of iodine and iodide. After a week of their research they informed me that they would be unable to make this product because the concentration of arsenic in the 3 mg dose would exceed California’s limit of acceptable levels.

Besides, these articles of the 60’s and 70’s studied the ‘nutritional’ intake of various cultures and even though they cite iodine and iodide being the primary variable for improving health we need to take into consideration all the nutrients in their diet, selenium being second in line.

My Recommendation

Obviously, some attention needs focus on iodine and iodide supplementation to secure the health of you and your loved ones. Here are a few suggestions.

  1. Use sea salt for cooking and for flavor. It contains many trace minerals which we no longer find in our produce. Sea salt does not contain nearly enough iodide. In fact the concentration of iodide in iodized salt is about 45 times that of sea salt.
  2. Use the combination of iodine and iodide at 3 mg a day for an adult, about half this for a child. The ratio is about 1.25 mg of iodine and 1.75 mg of potassium iodide.
  3. Always, always take selenium when taking any iodine product. I suggest between 200 and 400 mcg in the methionine form. Selenium plays hundreds of important roles in health and especially with thyroid hormones.

You’ll find more information on the safe uses of iodine and iodide on my blog while I continue to contribute to the ezine platform.

All the best,

Dr. Alexander Haskell, N.D.