Iodine is important for thyroid, brain, fertility, pregnancy and many other conditions. This critical mineral also protects breast tissue and eases symptoms of oestrogen dominance. 

What does iodine do for the body? Iodine is necessary for thyroid function, of course. It is one of the main building blocks of thyroid hormone.

But, did you know that 70% of the iodine in the body is distributed in other tissues? The developing brains of children have a high need for iodine, and adult brains need iodine for healthy concentration.

Iodine also boosts metabolic rate and assists with weight loss. It modulates and supports immune function, and acts as an anti-oxidant.

Iodine is also important for the prevention of cancer. Studies show that iodine deficiency correlates with an increased risk of stomach and breast cancer. One way that iodine prevents cancer, is that is signals cancer cells to die (apoptosis). It also protects female reproductive tissues such as breast, ovaries, and uterus from the over-stimulating effects of oestrogen. When the oestrogen receptor lacks iodine, it stimulates tissue to divide more rapidly (1).

Iodine deficiency is a cause of oestrogen dominant conditions such as breast cysts, ovarian cysts, and fibroids.Supplementing iodine is one of the fastest ways to relieve painful breasts, and it also protects them from cancer!

A simple urinary test for iodine is available from Sensible-Alternative Clinic.

How can we be sure to obtain enough of this essential mineral?

In countries like Australia where the soil is iodine-deficient, the only reliable food source of iodine is seafood and seaweed. Iodine deficiency is so widespread in Australia, that a program of bread fortification was recently undertaken.

Iodine supplements are available and are recommended for pregnant and breastfeeding women.

Salt is not iodine.

Table salt is sodium chloride and does not contain iodine unless it is fortified. Historically, table salt was fortified, but that practice was discontinued in recent decades. Today, many people use sea salt, which does not contain a significant amount of iodine. Iodised sea salt is available in supermarkets.

Are iodine supplements safe?

(See Lara's article "Is your iodine supplement safe?" for a warning about megadose iodine.)

Some caution should be used with iodine supplements. Too much iodine will suppress thyroid and metabolic rate. Even moderately high doses of iodine can worsen autoimmune thyroid conditions like Hashimoto's thyroid disease.

That said, if an iodine deficiency has been established with a urine test, then a small dose of iodine is certainly indicated.

Iodine is not the solution for every thyroid problem, but it should be supplemented when needed for deficiency. If not for the thyroid alone, then for all the other tissues in the body that require iodine. If the iodine deficiency is not corrected, then the body will harvest iodine from the thyroid hormone medication.


Stoddard FL et al. Iodine Alters Gene Expression in the MCF7 Breast Cancer Cell Line: Evidence for an Anti-Estrogen Effect of Iodine. Int J Med Sci. 2008; 5(4): 189-196