Iodine Doses for Optimal Benefits

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Iodine is an essential trace element, recognized for its cornucopia of important health benefits, including the traditional role it plays in the production of the thyroid hormones T3 and T4. Thyroid hormones regulate metabolism and energy production throughout the body and, in turn, affect core body temperature, growth, reproduction, proteins for the hair and skin, and the health of the muscles and joints. (1,2) Thus, iodine can pack a much-needed punch in keeping us healthy and vital.

In addition to its well-known role in thyroid health, iodine has antioxidant activity, and plays a critical role in intellectual development, hormone balance, and breast and reproductive system health. (2-8) While much of the body’s iodine is concentrated in the thyroid and thyroid hormones, 70% of the body’s iodine is distributed in other tissues, including the breasts, ovaries, eyes, stomach, cervix, and salivary glands. (3,8,9) In fact, nursing mothers have more iodine in the breast tissue than in the thyroid gland.

Sources of Iodine

Iodine must be obtained from the diet or in supplement form. Iodine intake through regular seaweed consumption – as seen in Japanese populations, for example – is naturally higher than in other populations. Current estimates put the Japanese daily intake of iodine from seaweed at 1-3 mg/day (10); but previous estimates have been much higher, such as 5.3-13.8 mg/day, and even as high as 50-80 mg/day! (2,3) As we will see below, there are varying recommendations for the optimal daily intake for iodine.

In other regions, the iodine content of food depends upon the presence and availability of iodine in the soil in which the food is grown. In many countries, table salt and cattle feed have been fortified with iodine to help consumers meet minimum intake requirements. For instance, universal salt iodization was instituted to reduce the prevalence of goiter. (11) It is interesting to note that over the last 25 years, the consumption of iodized table salt by US citizens has actually decreased by 65% as a result of people trying to reduce their sodium intake for health reasons. (2)

How Much Iodine Do You Need?

The exact amount of iodine the body needs is a controversial topic. The US recommended daily intake for iodine is 150 mcg/day for adults, and the FDA’s limit is set at 1 mg/day. Among functional medicine practitioners, there is no consensus on the actual human requirement for daily iodine. Some believe that individual iodine requirements hinge upon the exposure to our consumption of goitrogens – substances in food or the environment that interfere with iodine utilization or thyroid hormone production. Examples of goitrogens include toxic halides (fluoride and bromide), organochlorides, perchlorates, cabbage, Brussels sprouts, soy, and several other foods. (1)

According to some iodine experts, the requirement of the whole human body for iodine is about 14 mg/day or more (6 mg/day needed for the thyroid gland, the rest for extra-thyroidal tissues). (12)

Doses ranging from 3 mg/day up to 50 mg/day have been used successfully in clinical practice. (2,11,13). Furthermore, it is a little-known fact that under certain circumstances, high doses of potassium iodide (up to 130 mg per day) can be used to saturate the thyroid and protect it in the event of a nuclear accident. (14)

Iodine for Breast Health

Next to the thyroid gland, the breasts and ovaries concentrate the most iodine. (3,9) The relationship between breast health and iodine levels has been studied for decades, and it has been proposed that inadequate iodine prohibits normal breast architecture from developing. (11) Moderately high doses of supplemental iodine have been used to promote breast comfort after animal and human studies suggested that such a protocol would have positive effects. For instance, one such study investigated the effect of high doses of iodine on breast health in women with normal thyroid function. The 3 and 6 mg/day doses resulted in significant improvement in breast comfort. (4,5) (It is important to note that individuals with a history of autoimmune thyroid pathologies were excluded from the study.)

Iodine Supplementation

A urine test is an accurate way to gauge your iodine levels before considering high dose iodine supplementation. A urinary spot test from your doctor can be a helpful screening, but the most precise measure of your iodine needs is a 24-hour urinary load test kit.

Based on a urine test, supplemental iodine has been found to be safe and well-tolerated in the non-organic, non-radioactive iodine/iodide form. (12) LifeSpa’s Iodine HP reflects the forms and ratios of iodine found in Lugol’s solution – a liquid combination of molecular iodine and potassium iodide that has been safely and effectively employed since 1829. (3,15,16) Iodine HP provides 12.5 mg of iodine per capsule, with a breakdown of 5 mg of molecular iodine and 7.5 mg of potassium iodide. Individuals should consult their healthcare practitioner prior to using high dosages of iodine regarding any medical conditions, including thyroid conditions, and any possible interactions with medications.

For maintenance, immunity, and breast health, I recommend 1-3 mg/day of iodine, which is about 1 capsule of Iodine HP per week or two. Based on your iodine levels, in healthy doses, this multi-faceted mineral can support your body’s function and vitality in myriad ways!

What are your iodine levels like? Are you supplementing with healthy levels of iodine in your diet?