15 Ways Your Body Tells You that You’re Deficient in Iodine

This mineral is no joke. Without it, your body will wreak havoc on itself. Here are the top things you need to know about it…

What Is Iodine?

Iodine—it’s not just an element found on the periodic table. It’s a trace mineral that the body needs in order to make thyroid hormones—specifically thyroid hormones thyroxine (T4) and triiodothyronine (T3). 

Thyroid hormones are responsible for your body’s metabolism, the regulation of muscle and digestive function, and the development of proper bone and brain development during pregnancy and infancy (1) (2).

In short, the amount of iodine in your diet is directly related to how well your metabolic rate is functioning.

Luckily, iodine can be found in the right foods, in some types of salt, and is available as a dietary supplement.

Benefits of Iodine

You may be wondering, “Okay, so what does iodine do? How is it used by our bodies?”

In comes thyroid-stimulating hormone (TSH), also known as thyrotropin.

TSH is released by the pituitary gland (a small pea-sized gland that controls essential bodily functions and overall wellbeing) to control thyroid hormone production and secretion (3). So, when TSH is released, it literally protects the body from hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid).

When TSH is secreted, the absorption of iodine in your thyroid increases, which then stimulates the formation and release of T3 and T4.

15 Signs of Iodine Deficiency

Here’s the kicker: When you’re deficient in iodine, TSH levels will remain elevated and produce what’s called a goiter—an abnormal enlargement of your thyroid gland, which is a sign that your body is trying to trap more iodine and produce thyroid hormones (4).

If you’re deficient in iodine, then you may have an underactive thyroid (hypothyroidism). 

Signs of hypothyroidism in adults include (5)…

  • Fatigue
  • Increased sensitivity to cold
  • Constipation
  • Dry skin
  • Weight gain
  • Puffy face
  • Muscle weakness
  • Elevated blood cholesterol levels
  • Pain or stiffness in the muscles and joints
  • Slowed heart rate
  • Thinning hair
  • Depression
  • Poor memory
  • A heavier-than-normal period in menstruating women
  • Enlargement of your thyroid (i.e. goiter)

What Causes Iodine Deficiency?

You now know the signs of iodine deficiency. Next, we need to look at what causes iodine deficiency. Iodine naturally occurs in soil, which will determine the amount of iodine in crops. Unfortunately, some regions of the world lack sufficient iodine in their soil, thus increasing the risk of iodine deficiency among those who consume foods primarily from those areas. To combat this, many countries have implemented salt iodization programs, which have drastically reduced the incidence of iodine deficiency worldwide (6).

Iodine deficiency disorder (IDD) is the most common cause of preventable mental impairment worldwide—with 2 billion individuals suffering from insufficient iodine intake. The regions most affected are south Asia and sub-Saharan Africa (7) (8).

Foods Rich in Iodine

There are a handful of foods rich in iodine that we can benefit from. But again, it ultimately depends on where your food was grown. If it was on iodine-deficient land, then you may still be lacking.

The following are foods that, when grown in an iodine-rich environment, will help you meet your iodine needs (6)…

  • Fish
  • Eggs
  • Nuts
  • Whole-wheat Bread
  • Brown Rice
  • Greek Yogurt
  • Milk
  • Liver
  • Beef
  • Chicken Breast
  • Corn
  • Broccoli
  • Banana
  • Lima Beans
  • Green Peas
  • Seaweed
  • Iodized Table Salt

Can I Have Too Much Iodine?

The easiest (and most cost-effective) way to control iodine deficiency is to iodize salt. Too much iodine far outweighs the risks of iodine deficiency.

A healthy adult will have about 15-20 milligrams of iodine, with 70-80% of it resting in the thyroid (7). Pregnant and breastfeeding women should aim more toward 20mg of iodine per day.

Final Thoughts on Iodine

Iodine is essential for the upkeep of critical bodily functions, but luckily, there are more than enough ways to stay sufficient.

If you’re feeling any signs of iodine deficiency, be sure to consult a healthcare professional. They can test for iodine deficiency with a urine test, blood test, iodine patch test, or an iodine loading test.

If it’s caught early, symptoms of iodine deficiency can often be reversed. However, if it’s not caught early enough (especially in children), side effects can be permanent.


  1. Iodine – Consumer
  2. https://www.yourhormones.info/glands/thyroid-gland/#:~:text=The%20thyroid%20gland%20produces%20hormones,of%20iodine%20from%20the%20diet
  3. https://www.yourhormones.info/glands/pituitary-gland/#:~:text=The%20pituitary%20gland%20is%20a,most%20other%20hormone%2Dsecreting%20glands.
  4. https://www.mayoclinic.org/diseases-conditions/goiter/symptoms-causes/syc-20351829#:~:text=A%20goiter%20(GOI%2Dtur),you%20to%20swallow%20or%20breathe
  5. Hypothyroidism – Symptoms and causes 
  6. Iodine – Health Professional Fact Sheet 
  7. Iodine-deficiency disorders
  8. Iodine requirements and the risks and benefits of correcting iodine deficiency in populations