From the Research
Patients with thyroid nodules and normal TSH levels should generally not take iodine supplementation unless specifically directed by their healthcare provider, as it may stimulate autonomous thyroid function in nodular tissue, potentially leading to hyperthyroidism or enlargement of existing nodules, as suggested by the most recent and highest quality study 1.
Key Considerations
- The standard approach for managing thyroid nodules involves monitoring nodule size through ultrasound, possibly performing fine needle aspiration if warranted, and regular TSH testing to ensure thyroid function remains normal.
- Iodine supplementation may be considered for patients living in iodine-deficient regions or with documented iodine deficiency, but this should be done under medical supervision and with careful monitoring of TSH levels to avoid subclinical hyperthyroidism, as noted in 2.
- The combination of levothyroxine and iodine therapy has been shown to be effective in reducing thyroid nodule volume in patients with nodular goiter, as demonstrated in the LISA study 2 and further supported by 1.
Important Factors to Consider
- The presence of normal TSH levels suggests that the thyroid is currently functioning properly despite the nodules, and maintaining this balance is important for thyroid health.
- In areas with sufficient dietary iodine intake, additional iodine may not be necessary and could potentially be harmful, as it may stimulate autonomous thyroid function in nodular tissue.
- The American Thyroid Association guidelines provide a framework for evaluating and managing thyroid nodules, but regional differences in iodine intake and thyroid disease prevalence should be taken into account, as discussed in 3.
Recommendations for Clinical Practice
- Patients with thyroid nodules and normal TSH levels should be monitored regularly with ultrasound and TSH testing to ensure thyroid function remains normal.
- Iodine supplementation should only be considered for patients with documented iodine deficiency or living in iodine-deficient regions, and should be done under medical supervision with careful monitoring of TSH levels.
- The combination of levothyroxine and iodine therapy may be considered for patients with nodular goiter, but this should be done under medical supervision and with careful monitoring of TSH levels to avoid subclinical hyperthyroidism.