RADIOACTIVE IODINE

I have been receiving a ton of questions over the past week about potassium iodide. Since the Earthquake and tsunami on March 11th, some areas in Japan are using potassium iodide to protect residents from thyroid damage due to radioactive iodine. The amount of radioactive material being released in the environment in Japan, and present in the environment of neighbouring countries, is still being determined. Please contact your local public health team if you are concerned about exposure in your area.

What is potassium iodide?
Potassium iodide is a salt of stable iodine. For the most part, we can get adequate amounts of stable iodine from the foods that we eat. Potassium iodide is a medicinal form of stable iodine.

How does it work?
Following a radiological or nuclear event, radioactive iodine is released into the air, and taken up through our lungs when we breathe. It can also contaminate local food supply and water supply and be ingested. Once present in the body, the thyroid gland will begin to rapidly absorb it/take it up. Potassium iodide competes with radioactive iodine at receptor sites. It fills these sites and prevents the thyroid from taking up any of the radioactive substance. Its action at these receptor sites lasts 24 hours, meaning the thyroid is unable to take up any more iodine (stable or radioactive) during that time.

What it does not do?
It is important to understand that potassium iodide does not protect the body as a whole from radioactive iodine, nor does it prevent any other body part from taking it up. Its actions are very specific to the thyroid. It has no effect on other radioactive elements, like cesium, nor the effects these elements may have on the body.

How much should you take?
Infants and children are at the highest risk of developing thyroid cancer due to an accumulation of radioactive iodine. Infants who are breast feeding still need some sort of supplementation, as the breast milk will not contain enough stable iodine to protect the infant from exposure. It is recommended that adults (18+) take a dose of 130 mg (or two 65 mg tabs), children ages 3-18 years should take only 65 mg, unless adult sized (at this time the adult dose is recommended). Infants and children between 1month - 3 years are recommended to take 32 mg. It is suggested that newborns take 16 mg.

A one time dose of potassium iodide is usually all that is recommended to protect an individual from radioactive iodine uptake by the thyroid. If there is a threat that radioactive iodine will be in the environment for longer than 24 hours, public health officials may inform the public to take the supplement for a few days in a row. Please ask the advice of your local healthcare practitioner or public health agency. There are several health risks associated with high dosage or long-term dosage of potassium iodide, especially in infants and children, or those with a pre- existing thyroid conditions. Too much iodine can actually create a thyroid issue in individuals where there was none before. Taking more than is recommended for a longer period of time will not offer any more protection and may be putting these individuals at risk of other health issues.

Supplements/How can we help:

Nature's Way Kelp (Ascophyllum Nodosum) - providing 396 mcg of iodine.

AOR's Thyro-100 - has 100 mcg of potassium iodide per capsule. It also contains a number of other herbs/nutrients to support thyroid function.

NOW Kelp - providing 150 mcg of iodine/tab.

Thyrosense (Womensense) Thyrosmart (Lorna Vanderhaeghe) - both have 50 mcg of potassium iodide, again in combination with other herb/nutrients to support thyroid function.

NAKA: Vegetable Iodine Drops - 1mg potassium iodide per 20 drops (= 50 mcg per drop).

There is very little information available as to the effectiveness of a Kelp source of iodine versus potassium iodide in event of a radiologic or nuclear event. Theoretically, given that a kelp is considered a 'stable iodine' source, it should be working the same way. Currently, only potassium iodide is being recommended to prevent radioactive iodine uptake by the thyroid.

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