Nutritional Supplement

Iodine

  • Women's Health

    Pregnancy and Postpartum Support

    Iodine is an essential nutrient for the development of the fetal thyroid gland which, in turn, is important for brain development.
    Pregnancy and Postpartum Support
    ×
    Iodine is an essential nutrient for the development of the fetal thyroid gland which, in turn, is important for brain development. Even mild iodine deficiency during pregnancy may have an adverse effect on cognitive function of the child.1 In a preliminary study of women in Italy, iodine deficiency severe enough to cause hypothyroidism during pregnancy was associated with an increased risk of attention deficit-hyperactivity disorder in their children.2 However, excessive iodine intake can also adversely affect the thyroid gland. Women who are pregnant or planning to become pregnant should ask their healthcare professional whether they should take a prenatal supplement that contains iodine.

    Pregnancy

    In one study, iodine deficiency during pregnancy was associated with the babies being born with increased ADHD risk. If you are pregnant or trying to get pregnant, discuss whether you might need iodine supplements with your doctor.
    Pregnancy
    ×
     

    In a preliminary study of women in Italy, iodine deficiency severe enough to cause hypothyroidism during pregnancy was associated with an increased risk of ADHD in their children.3 Women who are contemplating pregnancy or who are pregnant should get adequate amounts of iodine in their diet and should discuss with their healthcare provider whether iodine supplementation is appropriate.

    Fibrocystic Breast Disease

    Iodine appears to be helpful in treating FBD, it should be taken only under the guidance of a healthcare practitioner.
    Fibrocystic Breast Disease
    ×
     

    Some doctors use iodine to treat FBD symptoms. In animals, iodine deficiency can cause the equivalent of FBD.4 What appears to be the most effective form—diatomic iodine5—is not readily available, however. Some people are sensitive to iodine and high amounts can interfere with thyroid function. Therefore, supplemental iodine should only be taken with the guidance of a healthcare practitioner.

  • Healthy Pregnancy and New Baby

    Pregnancy and Postpartum Support

    Iodine is an essential nutrient for the development of the fetal thyroid gland which, in turn, is important for brain development.
    Pregnancy and Postpartum Support
    ×
    Iodine is an essential nutrient for the development of the fetal thyroid gland which, in turn, is important for brain development. Even mild iodine deficiency during pregnancy may have an adverse effect on cognitive function of the child.6 In a preliminary study of women in Italy, iodine deficiency severe enough to cause hypothyroidism during pregnancy was associated with an increased risk of attention deficit-hyperactivity disorder in their children.7 However, excessive iodine intake can also adversely affect the thyroid gland. Women who are pregnant or planning to become pregnant should ask their healthcare professional whether they should take a prenatal supplement that contains iodine.

    Pregnancy

    In one study, iodine deficiency during pregnancy was associated with the babies being born with increased ADHD risk. If you are pregnant or trying to get pregnant, discuss whether you might need iodine supplements with your doctor.
    Pregnancy
    ×
     

    In a preliminary study of women in Italy, iodine deficiency severe enough to cause hypothyroidism during pregnancy was associated with an increased risk of ADHD in their children.8 Women who are contemplating pregnancy or who are pregnant should get adequate amounts of iodine in their diet and should discuss with their healthcare provider whether iodine supplementation is appropriate.

  • Children's Health

    Attention Deficit–Hyperactivity Disorder

    In one study, iodine deficiency during pregnancy was associated with the babies being born with increased ADHD risk. If you are pregnant or trying to get pregnant, discuss whether you might need iodine supplements with your doctor.
    Attention Deficit–Hyperactivity Disorder
    ×
     

    In a preliminary study of women in Italy, iodine deficiency severe enough to cause hypothyroidism during pregnancy was associated with an increased risk of ADHD in their children.9 Women who are contemplating pregnancy or who are pregnant should get adequate amounts of iodine in their diet and should discuss with their healthcare provider whether iodine supplementation is appropriate.

  • Weight Management

    Hypothyroidism

    Iodine deficiency and excessive iodine intake can both lead to hypothyroidism, so ask your doctor if supplementing with iodine is right for you.
    Hypothyroidism
    ×
     

    The relationship between iodine and thyroid function is complex. Iodine is required by the body to form thyroid hormone, and iodine deficiency can lead to goiter and hypothyroidism.10 Severe and prolonged iodine deficiency can potentially lead to serious types of hypothyroidism, such as myxedema or cretinism. It is estimated that one and a half billion people living in 118 countries around the world are at risk for developing iodine deficiency.11

    Today, most cases of iodine deficiency occur in developing nations. In industrialized countries where iodized salt is used, iodine deficiency has become extremely rare. On the other hand, iodine toxicity has become a concern in some of these countries.12 Excessive iodine intake can result in either hypothyroidism13 or hyperthyroidism (overactive thyroid).14 Sources of iodine include foods (iodized salt, milk, water, seaweed, ground beef), dietary supplements (multiple vitamin-mineral formulas, seaweed extracts), drugs (potassium iodide, amiodarone, topical antiseptics), and iodine-containing solutions used in certain laboratory tests. Many nutritional supplements contain 150 mcg of iodine. While that amount of iodine should prevent a deficiency, it is not clear whether supplementing with iodine is necessary or desirable for most people. Those wishing to take a nutritional supplement containing iodine should consult a doctor.

What Are Star Ratings?
×
Reliable and relatively consistent scientific data showing a substantial health benefit.
Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

Temp Title
×
Temp Text

References

1. Bath SC, Steer CD, Golding J, et al. Effect of inadequate iodine status in UK pregnant women on cognitive outcomes in their children: results from the Avon Longitudinal Study of Parents and Children (ALSPAC). Lancet. 2013;382:331–7.

2. Vermiglio F, Lo Presti VP, Moleti M, et al. Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: a possible novel iodine deficiency disorder in developed countries. J Clin Endocrinol Metab 2004;89:6054-60.

3. Vermiglio F, Lo Presti VP, Moleti M, et al. Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: a possible novel iodine deficiency disorder in developed countries. J Clin Endocrinol Metab 2004;89:6054-60.

4. Krouse TB, Eskin BA, Mobini J. Age-related changes resembling fibrocystic disease in iodine-blocked rat breasts. Arch Pathol Lab Med 1979;103:631-4.

5. Ghent WR, Eskin BA, Low DA, Hill L. Iodine replacement in fibrocystic disease of the breast. Can J Surg 1993;36:453-60.

6. Bath SC, Steer CD, Golding J, et al. Effect of inadequate iodine status in UK pregnant women on cognitive outcomes in their children: results from the Avon Longitudinal Study of Parents and Children (ALSPAC). Lancet. 2013;382:331–7.

7. Vermiglio F, Lo Presti VP, Moleti M, et al. Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: a possible novel iodine deficiency disorder in developed countries. J Clin Endocrinol Metab 2004;89:6054-60.

8. Vermiglio F, Lo Presti VP, Moleti M, et al. Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: a possible novel iodine deficiency disorder in developed countries. J Clin Endocrinol Metab 2004;89:6054-60.

9. Vermiglio F, Lo Presti VP, Moleti M, et al. Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: a possible novel iodine deficiency disorder in developed countries. J Clin Endocrinol Metab 2004;89:6054-60.

10. Thilly CH, Swennen B, Bourdoux P, et al. The epidemiology of iodine-deficiency disorders in relation to goitrogenic factors and thyroid-stimulating-hormone regulation. Am J Clin Nutr 1993;57(2 Suppl):267S-70S.

11. Delange F. Risks and benefits of iodine supplementation. Lancet 1998;351:923-4.

12. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol Metab 1991;73:213-5.

13. Chow CC, Phillips DIW, Lazarus JH, Parkes AB. Effect of low dose iodide supplementation on thyroid function in potentially susceptible subjects: are dietary iodide levels in Britain acceptable? Clin Endocrinol 1991;34:413-6.

14. Stewart JC, Vidor GI. Thyrotoxicosis induced by iodine contamination of food: a common unrecognized condition? Br Med J 1976;1:372-5.

15. Gaby, AR. Nutritional Medicine. Concord, NH: Fritz Perlberg Publishing, 2011.

16. Hollowell JG, Staehling NW, Hannon WH, et al. Iodine nutrition in the United States. Trends and public health implications: iodine excretion data from National Health and Nutrition Examination Surveys I and III (1971-1974 and 1988-1994). J Clin Endocrinol Metab 1998;83:3401-8.

17. Mu L, Derun L, Chengyi Q, et al. Endemic goiter in central China caused by excessive iodine intake. Lancet 1987;2:257-9.

18. Heymann WR. Potassium iodide and the Wolff-Chaikoff effect: Relevance for the dermatologist. J Am Acad Dermatol. 2000 Mar;42:490-2.

19. Pennington JA. A review of iodine toxicity reports. J Am Diet Assoc 1990;90:1571-81.

20. Williams ED, Doniach I, Bjarnason O, et al. Thyroid cancer in an iodide rich area. Cancer 1977;39:215-22.

21. Kim JY, Kim KR. Dietary iodine intake and urinary iodine excretion in patients with thyroid diseases. Yonsei Med J. 2000;41:22-8.

22. Harach HR, Williams ED. Thyroid cancer and thyroiditis in the goitrous region of Salta, Argentina, before and after iodine prophylaxis. Clin Endocrinol (Oxf) 1995;43:701-6.

23. Harach HR, Escalante DA, Onativia A, et al. Thyroid carcinoma and thyroiditis in an endemic goitre region before and after iodine prophylaxis. Acta Endocrinol (Copenh) 1985;108:55-60.

24. Papanastasiou L, Alevizaki M, Piperingos G, et al. The effect of iodine administration on the development of thyroid autoimmunity in patients with nontoxic goiter. Thyroid 2000;10:493-7.

Copyright © 2025 TraceGains, Inc. All rights reserved.

Learn more about TraceGains, the company.

The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.