Iodine
As an essential nutrient, iodine is needed for thyroid function, and a deficiency is linked to higher risk of thyroid and stomach cancers. Some evidence shows that treatment with molecular iodine before breast cancer surgery may improve tumor response and reduce some side effects.
Iodine at a glance
Iodine is a mineral and essential nutrient found in foods including fish, seafood, kelp, dairy products, eggs, and iodized salt. Because iodine deficiency is a cause of underactive thyroid (hypothyroidism), corrective treatment with supplemental iodine may enable an underactive thyroid to resume making thyroid hormones that influence bone and brain development as well as other functions. A thyroid hormone deficiency or insufficiency may also contribute to cancer growth or other conditions.
Radioactive iodine is widely used as a conventional treatmentthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy for many types of cancer and also overactive thyroid (hyperthyroidism). Additional experimental uses of radioactive iodine are being investigated. Information on these treatments is widely available from conventional treatment sources.
In this review, we assess the impact of iodine deficiency and use of dietary iodine or molecular iodine supplements in cancer care. To date, very little research has investigated this use of molecular iodine supplements. One small study found better survival and tumor response rates, plus fewer side effects of treatment, when molecular iodine was used in addition to surgery and chemotherapy for breast cancer. An iodine deficiency may increase the risk of thyroid cancer or stomach cancer. No evidence shows that iodine supplements as a stand-alone treatment will improve cancer outcomes.
CancerChoices ratings for iodine
We rate iodine on seven attributes, with 0 the lowest rating and 5 the highest. We rate the strength of the evidence supporting the use of iodine for a medical benefit, such as improving treatment outcomes or managing side effects.
See how we evaluate and rate complementary therapies ›
Improving treatment outcomes
See More- Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of better survival and tumor response rates among women with breast cancer treated with molecular iodine before and after surgery compared to after surgery alone
- Preliminary evidence of comparable radioiodine consumption after radioiodine ablation therapy following a total thyroidectomy among Korean people following either a low-iodine diet (less than 50 µg iodine) or a restricted-iodine diet (50–100 µg)
Optimizing your body terrain
See MoreWe did not find any published studies investigating iodine’s use for managing body terrainthe internal conditions of your body, including nutritional status, fitness, blood sugar balance, hormone balance, inflammation and more factors.
Managing side effects and promoting wellness
See More- Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of less neutropeniaan abnormally low number of neutrophils in the blood, leading to increased susceptibility to infection, cardiotoxicity, hand-foot syndrome, nausea, vomiting, or diarrhea from chemotherapy among women with breast cancer treated with molecular iodine before and after surgery compared to after surgery alone
- No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on muscle pain among women with stage 2 or 3 breast cancer treated with molecular iodine
Reducing cancer risk
See More- Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of a link between iodine deficiency and risk of stomach cancer
- Modest evidence of a link between iodine deficiency and risk of thyroid cancer; also see information about higher risk of thyroid cancer among people with high intakes of iodine in Safety and precautions ›
Use by integrative oncology experts
See More- Limited use by our program sources
- Not mentioned in clinical practice guidelines for cancer care
Safety
See More- Moderate caution is needed, and supervision by a medical professional is highly recommended.
- Some evidence of higher risk of breast cancer among people with high urinary levels of iodine.
- High intake of iodine can cause health risks related to the thyroid gland, and overdose can result in acute poisoning symptoms.
- Iodine can interact with many medications.
Affordability and access
See More- Available without a prescription
- Low to moderate cost (below $2000 US/year) for supplements
- Various formulations of iodine are available, with differences in their use and effectiveness for cancer.
Keep reading about iodine
Authors
Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.
Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.
For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.
Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.
Reviewer
Susan Yaguda, MSN, RN
Susan Yaguda, MSN, RN, has been a nurse for nearly 40 years, working in a variety of healthcare settings. She currently works in Charlotte, North Carolina, at Atrium Health’s Levine Cancer Institute as the manager for Integrative Oncology and Cancer Survivorship. She works with a multidisciplinary team to deliver holistic, evidence-based support and education for patients and care partners at any point along the trajectory of cancer care. She completed the Integrative Oncology Scholars Program through the University of Michigan in 2020, is certified as an Integrative Health Coach through Duke Integrative Medicine and has a post-graduate certificate in Nursing Education from the University of North Carolina, Charlotte. Susan also was awarded the Planetree International Scholar’s Award in 2018 and was recognized by the Daisy Foundation for Nurse Leadership in 2021. Susan has a particular interest in empowering patients and care partners with knowledge to help drive informed decision making and educating nurses on the benefits of integrative care for patients and self-care. She has presented nationally and internationally on integrative oncology and nursing education.
She and her husband, Mark, have two adult children and a very spoiled foxhound. She enjoys hiking, knitting, cooking, and pickleball.
“As a frequent consumer of Beyond Conventional Cancer Therapies, and now CancerChoices, for both professional education and patient support, it is an honor to have the opportunity to engage with the dedicated team at CancerChoices to serve those impacted by this disease.”
Last update: December 12, 2023
Last full literature review: April 2023
We are grateful for research support from Adriana Gutierrez Galvis.
CancerChoices provides information about integrativein cancer care, a patient-centered approach combining the best of conventional care, self care, and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocialtherapy, and acupuncture therapies and self carelifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.
Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.