From the Guidelines
Iodine is essential for proper thyroid function, and adults need about 150 micrograms of iodine daily, with higher requirements for pregnant and breastfeeding women, to maintain healthy thyroid function and prevent deficiency disorders, as supported by the most recent and highest quality study 1. The recommended daily intake of iodine varies by age and pregnancy status, with the World Health Organization (WHO) recommending 250 µg/d for pregnant women, as stated in the study 1. Some key points to consider include:
- Iodine deficiency can lead to hypothyroidism, goiter (enlarged thyroid), and developmental issues in children, while excessive intake can cause hyperthyroidism or thyroiditis, as noted in the study 1.
- Good dietary sources of iodine include iodized salt, seafood, dairy products, and some breads, as mentioned in the study 1.
- For those with confirmed deficiency, supplements containing potassium iodide (typically 150 mcg daily) may be recommended, but should only be taken under medical supervision, as suggested in the study 1.
- The thyroid uses iodine to produce hormones that regulate metabolism, growth, and development, making this relationship crucial for overall health, as highlighted in the study 1. In regions with iodine-poor soil, using iodized salt is particularly important for preventing deficiency disorders, as emphasized in the study 1. It is also important to note that the Tolerable Upper intake level (UL) for adults is 1.1 mg/day, as stated in the study 1, and that excessive intake can cause adverse effects, such as hyperthyroidism or thyroiditis. Overall, maintaining adequate iodine intake is crucial for preventing deficiency disorders and ensuring overall health, as supported by the most recent and highest quality study 1.
From the FDA Drug Label
Certain forms of iodine help your thyroid gland work right. The thyroid can “store” or hold only a certain amount of iodine. If you take KI, it will block or reduce the chances that radioactive iodine will enter your thyroid gland.
The thyroid gland uses iodine to function properly. Potassium iodide (KI) can help block or reduce the uptake of radioactive iodine by the thyroid gland 2.
- Key points:
- Iodine is essential for thyroid function.
- KI can help protect the thyroid gland from radioactive iodine.
- Patients with certain thyroid conditions should use KI with caution or under medical supervision 2.
From the Research
Iodine and Thyroid Function
- The thyroid gland plays a crucial role in collecting iodine, with the active iodine uptake along the basolateral membrane of thyroid cells followed by its transport to the apical edge of the cell and then to the follicle lumen 3.
- The recommended daily intake of iodide is 150 μg for adolescents and adults, 250 μg for pregnancy and lactation, and excessive iodine intake can lead to hypothyroidism or hyperthyroidism 3.
Iodine Treatment for Thyroid Conditions
- Potassium iodide (KI) is used as an initial pharmacologic treatment for thyroid storm, and its clinical efficacy remains unexplored 4.
- A study found that KI use was not significantly associated with in-hospital mortality, but it may reduce in-hospital mortality among patients hospitalized for thyroid storm with Graves' disease 4.
- KI therapy is useful in the treatment of Graves' hyperthyroidism, with a sufficient dose of KI effective in >50% of patients from 4 weeks to 2 years 5.
- Combining methimazole with inorganic iodine may be superior to methimazole alone as a primary treatment for moderate to severe hyperthyroidism caused by Graves' disease 6.
Benefits of Iodide Supplementation
- Short-term iodide supplementation to antithyroid drug treatment of thyrotoxicosis due to Graves' disease can improve the rapid normalization of thyroid hormones during the early phase 7.
- Combined treatment with methimazole and potassium iodide can improve the short-term control of Graves' hyperthyroidism without worsening hyperthyroidism or inducing thionamide resistance 7.