IodineDoes iodine boost the immune system?
Updated 10 Nov 2026
Short answer
NIH ODS says that iodine appears to have a role in the immune response.[1] No trial found in PubMed searches tested iodine supplements taken by mouth against colds or other infections.
Some trials of iodine against infection and for wound healing used iodine antiseptics on the skin or in wounds. In one, a rinse of the wound with dilute povidone-iodine before closing it lowered infections after repeat hip and knee replacement from 3.4% to 0.4%.[2] In another, cadexomer iodine on chronic ulcers healed 58% to 66% of them in 12 weeks, against 20% with standard care.[3] These trials tested iodine on the body, not iodine supplements.[2][3]
Sources (3)
- Iodine: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
- 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
- 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 is iodine used for?What happens if you do not get enough iodine?Is iodine safe?Do you need an iodine supplement in pregnancy?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.