A low-iodine diet was developed for used in decreasing iodine intake and excretion in patients undergoing evaluation with radioactive I-131 for ablation of thyroid remnants as treatment for thyroid cancer. It has been demonstrated to effectively lower iodine excretion to less than 25% of basal values. Preliminary calculations suggest that such iodine depletion may be potentially useful in increasing the radiation dose per mCi of administered activity in I-131 ablative therapy.