Iodine supplementation to increase milk supply

by Laura Howells
4 mins reading time
(Updated )

Letter blocks spelling out “iodine” potato’s, milk, shrimp, tuna, sardines, and other foods all laid out on a cutting board

Pregnancy and lactation are nutritionally incredibly important times in a woman's/person’s life.

During these periods and even before pregnancy, it's important to pay attention to what you are eating and to make sure you're getting all the necessary nutrients to support your own health and the health of your baby. One nutrient that's especially important during pregnancy and lactation is iodine.

Iodine is an essential mineral that's necessary for the proper functioning of the thyroid gland. The thyroid gland produces hormones that regulate metabolism and growth, and iodine is necessary for the production of these hormones. During pregnancy and lactation, the demand for iodine increases, as the baby relies on the parent to supply the nutrient.

How much iodine do I need and where do I get it?

The American Academy of Pediatrics recommends that pregnant and lactating women consume 290 mcg of iodine per day. This is an increase from the 220 mcg per day recommended for non-pregnant, non-lactating women.

Sources of iodine include seafood, dairy products, and sea weed. Iodized salt is also another way people increase their iodine intake but it isn’t reliable as most premade foods do not use iodized salt, the iodine does evaporate from the salt over time and it is very hard to quantify how much iodine you are getting this way. Also the salt that often has added iodine tends to be low quality. If you are someone that is likely to take a supplement it may make more sense to buy a higher quality salt with no iodine and then supplement iodine as needed. Most people will not get enough iodine through eating dairy products and sea weed alone.

What is stopping me from absorbing iodine?

Fluoride, chloride and bromide can block receptor sites where the body needs iodine and stop if from being able to absorb the iodine it needs. If you are iodine deficient it is worth looking into wether you need to decrease your exposure to fluoride, chloride and bromide in order to properly be able to absorb your bodies needed iodine. Fluoride can be found in tap water, toothpaste and mouth washes. Most water purification systems do not remove fluoride. Chloride is found in tap water and swimming pools. Bromide is found in pesticides and is used as a flame retardent, it is also found in swimming pools and trace amounts in breads.

A lack of iodine during pregnancy and lactation can have serious consequences for both the parent and the baby. Inadequate iodine intake during pregnancy can lead to hypothyroidism, which if left untreated can cause developmental delays, intellectual disability, and other health problems in the baby as well as insufficient milk supply. In addition, iodine deficiency during pregnancy can increase the risk of miscarriage and stillbirth.

Insufficient glandular tissue and iodine deficiency

During pregnancy and lactation, a lack of iodine can also have serious consequences. Iodine is necessary for the production development of glandular tissue, the part of the breasts/chests that makes and stores human milk. There should be growth of the glandular tissue during pregnancy and into the postpartum period. Without the needed iodine we are seeing a decrease in the number of parents who are able to make a full milk supply.

It's important to note that too much iodine can also be harmful, so it's important to talk to your healthcare provider about your individual needs and to follow their recommendations for iodine intake.

Iodine's impact on breast health and treatment of breast cancer

One study, published in the Journal of Surgical Research, found that iodine supplementation may help decrease the risk of breast cancer in women with benign breast disease. The researchers noted that iodine has been shown to have anti-inflammatory and antioxidant properties, which may help prevent the development of cancer.

Interestingly, iodine may also have a role to play in the treatment of breast cancer. A study published in the Journal of Surgical Oncology found that a combination of iodine and tamoxifen, a drug commonly used to treat breast cancer, was more effective in inhibiting the growth of breast cancer cells than tamoxifen alone.

While more research is needed to fully understand the role of iodine in breast health, these studies suggest that iodine may play an important role in the growth of glandular tissue and the prevention of breast cancer.

In conclusion, iodine is an essential nutrient that's especially important during pregnancy, lactation and beyond. Getting enough iodine through diet and/or supplements can help support the health of both the mother/parent and the baby. Talk to your healthcare provider about your individual needs to make sure you're getting the right amount of iodine for your specific situation. Your OB may not be knowledgeable on this subject you may need to speak with a naturopath, functional medicine doctor or nutritionist who has more training in nutrition.


  1. Aceves, C., Anguiano, B., & Delgado, G. (2009). The Extrathyronine Actions of Iodine as Antioxidant, Apoptotic, and Differentiation Factor in Various Tissues. Thyroid, 19(9), 9-10.
  2. Eskin, B. A. (2005). Iodine and mammary gland health. Journal of Mammary Gland Biology and Neoplasia, 10(4), 379-382.
  3. Smyth, P. P., & Shering, S. G. (2003). Iodine supplementation in women with benign breast disease. Journal of Surgical Research, 113(1), 133-136.
  4. Funahashi, H., Imai, T., & Tanaka, Y. (1996). Iodine inhibits tumor growth and metastasis in mouse mammary cancer model. Journal of Surgical Oncology, 61(3), 209-213. https
  5. American Academy of Pediatrics. (2014). Iodine Supplementation for Pregnant and Breastfeeding Women. Pediatrics, 133(6), e1673-e1682.
  6. Leung, A. M., & Braverman, L. E. (2014). Iodine in pregnancy and lactation. Endocrinology and Metabolism Clinics of North America, 43(2), 567-582.
  7. Zimmermann, M. B. (2009). Iodine deficiency in pregnancy and the effects of maternal iodine supplementation on the offspring: a review. American Journal of Clinical Nutrition, 89(2), 668S-672S.
  8. World Health Organization. (2007). Assessment of Iodine Deficiency Disorders and Monitoring Their Elimination: A Guide for Programme Managers (3rd ed.). WHO Press.
  9. National Institutes of Health. (2021). Iodine: Fact Sheet for Health Professionals.


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Laura Howells (she/her) is an IBCLC and postpartum doula who works with clients in the San Francisco Bay Area. She has been happily supporting growing families during pregnancy, birth, postpartum, and the first years since 2009.

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