Iodine

What is iodine used for?

Updated 10 Nov 2026

Short answer

Iodine supplements are mostly studied to prevent or correct iodine deficiency. Deficiency can cause goiter and can harm the growth and brain of a child.[1]

What the best studies found:

  • children with low iodine: a 2026 Cochrane review found a slight gain in thinking skills, and likely fewer cases of hypothyroidism and fewer deaths in infants. It found little or no effect on growth[2]
  • pregnancy: supplements raise the mother's iodine level, but reviews found no clear effect on the child's development or size at birth[3][4]
  • breast pain: two small trials found less pain with high doses, above the upper limit[1]

Some trials of iodine against infection and for wound healing used iodine antiseptics on the skin or in wounds, not supplements.[5][6]

Sources (6)

  1. Iodine: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  2. Iodine supplementation for preventing iodine deficiency disorders in children and adolescents. Velasco I, Rueda-Etxebarria M, Trak-Fellermeier MA, Taylor P, Rabassa Bonet M, Chi Y, et al. Cochrane Database Syst Rev, 2026. PMID 42720098
  3. Systematic review and meta-analysis of the effects of iodine supplementation on thyroid function and child neurodevelopment in mildly-to-moderately iodine-deficient pregnant women. Dineva M, Fishpool H, Rayman MP, Mendis J, Bath SC Am J Clin Nutr, 2020. PMID 32320029
  4. Effects of iodine supplementation during pregnancy on pregnant women and their offspring: a systematic review and meta-analysis of trials over the past 3 decades. Nazeri P, Shariat M, Azizi F Eur J Endocrinol, 2021. PMID 33112293
  5. Dilute Betadine Lavage Reduces the Risk of Acute Postoperative Periprosthetic Joint Infection in Aseptic Revision Total Knee and Hip Arthroplasty: A Randomized Controlled Trial. Calkins TE, Culvern C, Nam D, Gerlinger TL, Levine BR, Sporer SM, et al. J Arthroplasty, 2020. PMID 31575448
  6. Efficacy of Cadexomer Iodine in the Treatment of Chronic Ulcers: A Randomized, Multicenter, Controlled Trial. Raju R, Kethavath SN, Sangavarapu SM, Kanjarla P Wounds, 2019. PMID 30720444

More about iodine

What is iodine?Which foods contain iodine?What happens if you do not get enough iodine?Is iodine safe?Do you need an iodine supplement in pregnancy?Does iodine help brain development in children?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.