Limits on iodine

How much iodine is too much?

That question comes from an HSI member named Sharon who wants a little more information about a new weight loss supplement called Weight Wellness. We told you about Weight Wellness two weeks ago (“A Little Help With America’s No. 1 Resolution” 1/1/03), and three days later this posting from Sharon appeared on the HSI Forum:

“The product contains 1800 mcg of iodine, along with 400mg of kelp. How does this much iodine affect the thyroid gland (possible problems down the road) as most recommendations are for 150 mcg? Can you have an iodine overload? I am 66, overweight, previous heart attack, (in good shape now) and have mild hypercholesterolemia which I am sure would go down with weight loss. Also am primarily vegetarian, with occasional lapses (LOL), no dairy, no egg yolks, occasional egg whites.”

The 400 mg of Atlantic Sea Kelp listed on the “Supplement Facts” panel of Weight Wellness, is actually the source of the 1,800 mcg of iodine. In other words, there’s no extra boost of iodine from the sea kelp, over and above the 1,800 mcg. (These two items are listed separately, as required by the FDA.)

For the answers to Sharon’s specific questions, I called on HSI Panelist, Allan Spreen, M.D., to help out. And here’s Dr. Spreen’s response:

“First of all, the RDA by the Food & Nutrition Board of the National Research Council are (in my opinion) far too low, in general, for optimal health (with the notable exception of iron which is far too high). The numbers listed have always been proposed, not for optimal health, but as minimums for the avoidance of overt disease.

“It is possible to ingest too much iodine (and kelp contains a lot of it). As to what that number is would be the subject of considerable debate (your doc should have the final say, of course). Excesses of iodine can over-stimulate the thyroid, which can be detected by various symptoms such as tremor, flushed sensation, rapid heart beat, increased blood pressure, feeling warm when everyone else is comfortable, increase in basal temperature (taken first thing in the morning), and others. In the absence of thyroid glandular extracts (or actual desiccated thyroid), these symptoms are much less common.

“It is more common, in my experience, that those with an overweight problem tend to be low in thyroid function, which is the intent of including iodine in this supplement (at least I assume thatI wasn’t involved in the formulation).

“I would suggest that, when you do ‘cheat’ and eat egg whites, that you include the yolk if your doc permits. That’s where the high-sulfur compounds reside, and sulfur is difficult for humans to adequately obtain in their diets. If you’re concerned about egg yolks and cholesterol (which have been studied and found not to affect serum cholesterol levels in moderate amounts), cook the egg without breaking the yolk, so the cholesterol is not oxidized.”

My thanks to Dr. Spreen, as always, for his insights and useful information. To his comments I would just add that the Weight Wellness supplement comes with a specific warning for individuals who are sensitive to iodine or have a history of thyroid problems. In any case, I strongly agree with Dr. Spreen that consultation with your physician is an important first step when beginning any new diet regimen.

To Your Good Health,

Jenny Thompson
Health Sciences Institute