The Low-Iodine Diet

Patients may be asked to take steps to deplete their body's natural store of iodine so the thyroid will more readily absorb the radioactive iodine treatment and maximize treatment effectiveness

To maximize the effectiveness of radioactive iodine, patients may be asked to take a couple of steps to deplete their body’s natural store of iodine so that the thyroid will more readily absorb the treatment.

To that end, patients are instructed to temporarily stop taking synthetic hormone pills, such as levothyroxine, which can often leave patients feeling very fatigued and irritable. A physician also may prescribe a low-iodine diet, most typically for a couple of weeks prior to treatment.

Stephanie Lee, MD, PhD, associate chief of endocrinology, diabetes, and nutrition at Boston Medical Center, says people will typically do fine if they follow several key guidelines:

Use non-iodized or kosher salt

Don’t consume dairy products, including milk, yogurt, or cream

Steer clear of seafood and seaweed

Avoid eggs, or at the very least egg yolks

Eat homemade bread if possible; otherwise, limit bread to one slice daily

Reading food labels to search for hidden iodine is helpful, but not universally reliable, Lee says. The Boston endocrinologist helped to author a study, published in 2004 in The Journal of Clinical Endocrinology & Metabolism, which scrutinized iodine content in bread. The researchers found that the amounts listed on the labels weren’t necessarily reflective of the quantity within the package.

For dietary details, the Thyroid Cancer Survivors’ Association provides a low-iodine resource on its website at www.thyca.org/rai.htm.