A growing number of you have been writing to me today re: radiation exposure due to nuclear reactor damage in Japan.

An as yet undetermined amount of radiation has already been released, with more likely. A cloud of radiation, creating the most immediate risk, could cross the Pacific, but this is unlikely and would take some days to do so. If this were to turn out to be the worst possible scenario, you have time before you would have to make a decision.

To be cautious, some of you have asked about taking potassium iodide to protect against thyroid cancer. There are many radioactive substances in nuclear reactors, so potassium iodide is not entirely effective. Anyone sensitive to iodine should not take it, and the usual adult dose of potassium iodide (100-150 mg NOT mcg – 1 mg = 1000 mcg) is enough to temporarily disturb thyroid metabolism in an individual whose thyroid gland is functioning poorly (overproducing or underproducing thyroid hormone). If you were to take potassium iodide, you would want to take it just as your exposure begins (6 hours plus or minus). Usually the dose would be taken just one time. If you were to take it too soon, you could take it again after 24 hours or so; however, you would be more likely to suffer adverse effects.

As it is always a challenge to get small children to take pills, the following link gives instructions on how to make potassium iodide palatable to children:


This is a low risk preventive measure, and so not entirely unreasonable to consider. However, I do not recommend that you take this step at this time. I do believe that having some on hand at home, as a part of your emergency kit, is a good idea.

It is always a good idea to drink lots of water, exercise and consume green leafy vegetables, antioxidant foods (veggies, berries, etc.), whether you are exposed to radiation or not. Although there are also antioxidant supplements and herbs that I sometimes recommend with medical radiation exposures (like the VITANOX combination), even that intermediate step would probably be an overreaction at this moment.

One list of adverse effects of potassium iodide-

Cardiovascular: Irregular heart beat

Central nervous system: Confusion, tiredness, fever

Dermatologic: Skin rash

Endocrine & metabolic: Goiter, salivary gland swelling/tenderness, thyroid adenoma, swelling of neck/throat, myxedema, lymph node swelling, hyper-/hypothyroidism

Gastrointestinal: Diarrhea, gastrointestinal bleeding, metallic taste, nausea, stomach pain, stomach upset, vomiting

Neuromuscular & skeletal: Joint pain, numbness, tingling, weakness

Miscellaneous: Hypersensitivity reactions (angioedema, cutaneous and mucosal hemorrhage, serum sickness-like symptoms)

Contraindications Hypersensitivity to iodine or any component of the formulation; dermatitis herpetiformis; hypocomplementemic vasculitis, nodular thyroid condition with heart disease


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Michael Carlston, MD is an internationally recognized authority in the integration of conventional and complementary medicine in clinical practice, as well as medical education, research and organizational consulting. Practicing in Santa Rosa, California, Dr. Carlston was voted “Best General Physician In Sonoma County, California” by readers of the Sonoma County Independent newspaper and also named one of the outstanding physicians in the Bay Area by San Francisco Focus Magazine. With 30+ years in private practice, his expertise is in nutrition, homeopathy and sports medicine.

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