Can Hair Loss Be a Sign of Iodine Deficiency?

Your hair is more than just a part of your appearance, it’s a reflection of your confidence and style. When hair loss occurs, it can feel like a setback — but there are many potential causes beyond just aging and genetics.

Nutritional deficiencies, for instance, can also play a role in your hair’s health. Just like the rest of the body, your hair and scalp need essential vitamins and minerals to grow. When our body lacks certain nutrients, this can lead to hair loss.

In particular, iodine (found in many foods and commonly added to table salt) deficiency can be a major concern as it plays a key role in thyroid health and interacts with thyroid hormones. 

Let’s take a closer look at this important mineral, explore the symptoms of iodine deficiency, and how low levels can contribute to hair loss. 

What Is Iodine?

Iodine is an essential trace mineral. It can’t be produced independently by the body, so it must be obtained through diet or iodine supplementation. In the gut, iodine is typically reduced to iodide. The body needs it to maintain proper function.

Where Is Iodine Found?

Iodine is found primarily in the ocean and in soil. You can find dietary iodine in a variety of sources, including animal proteins and sea vegetables.. The average daily recommended amount of iodine in healthy adults is 150 micrograms (mcg). 

Dietary iodine can be found in:

  • Seaweed like kelp
  • Fish and shellfish (e.g. cod and shrimp)
  • Dairy products
  • Iodized salt (table salt)
  • Beef liver 
  • Fortified infant formulas

Thyroid Function and Iodine

One of the most essential roles iodine plays in the body is supporting the health and function of the thyroid gland. The thyroid is a small, butterfly-shaped endocrine gland located on the front of the neck, in front of the trachea. 

The thyroid plays a critical role in the endocrine system regarding hormone regulation. Hormones act as chemical messengers that help coordinate bodily functions, from metabolism to reproduction. 

Other organs and glands that make up the endocrine system include the hypothalamus, pituitary gland, adrenal glands, pancreas, pineal gland and more. The thyroid’s main job is to produce and secrete hormones that help regulate metabolism. 

The thyroid produces and secretes several hormones, including thyroxine (T4), triiodothyronine (T3), and reverse triiodothyronine (RT3). This hormone release is triggered by thyroid stimulating hormone (TSH), which is released by the pituitary gland. 

Thyroid hormones affect many boldly functions, including:

  • Heart rate 
  • Breathing 
  • Body temperature 
  • Digestion 
  • Bone maintenance
  • Brain development
  • Fertility 

The average healthy adult contains around 15 to 20 mg of iodine, and roughly 70 to 80 percent of iodine is housed within the thyroid. The body uses around 60 to 95 mcg a day for proper function.

One of the main roles of iodine for thyroid function is to decrease thyroid response to TSH and inhibit thyroid hormones when levels get too high. After use, it is excreted as urinary iodine.

A Look at Iodine Deficiency

In short, iodine deficiency can prevent proper growth and development. According to the World Health Organization, the prevalence of iodine deficiency is widespread. Approximately 1.88 billion worldwide have insufficient dietary iodine intake. Iodine deficiency is a significant health concern in underdeveloped countries, which increases the risk of various health issues. 

Since children are still developing, low iodine levels and severe iodine deficiency can inhibit proper brain development. This can lead to physical problems, cognitive issues, and even brain damage. 

According to the American Thyroid Association, most symptoms of iodine deficiency are related to its effects on the thyroid gland. The key issue is low levels of thyroid hormones, which can contribute to various thyroid diseases

Signs of iodine deficiency include:


When the body lacks iodine, it causes the thyroid to get larger as it tries to meet the demands of thyroid hormone production. Abnormalities known as goiters can develop. 

Goiters are essentially an enlargement of the thyroid gland. It is marked by swelling at the neck. Goiters can cause pressure-related symptoms like difficulty swallowing, coughing and more. 

Hypothyroidism (Underactive Thyroid)

As iodine levels fall, an iodine deficiency disorder known as hypothyroidism can develop. Not to be confused with hyperthyroidism (overactive thyroid), this condition occurs when not enough thyroid hormones are released. This can slow metabolism, leading to weight gain, among other issues. 

Some signs of hypothyroidism include:

  • Fatigue and lethargy 
  • Sensitivity to cold temperature
  • Constipation
  • Dry skin and hair

A similar thyroid disease called Hashimoto’s disease is an autoimmune disorder that essentially attacks healthy thyroid cells. Although its symptoms can mirror hypothyroidism in many ways, these are two separate disorders with different causes.

Issues with iron deficiency are important to monitor for pregnant and breastfeeding women. Low iodine and severe iodine deficiency can cause pregnancy issues. These include miscarriage, stillbirth, preterm delivery, congenital abnormality, and cretinism. 

Vegans and those who do not eat animal products are at greater risk for low iodine status and deficiency. Additionally, individuals living in regions with low levels of iodine in the soil and minimal iodine in their diet may have a higher risk of deficiency. Iodine levels can be confirmed through urine or blood tests. 

Iodine Deficiency and Hair Loss

You might not think of hair loss as a typical symptom of iodine deficiency, but it’s more connected than you might imagine. Iodine plays a crucial role in thyroid function, and when your thyroid hormones are out of balance, it can affect your hair follicles and lead to excess shedding.

Healthy hair starts at the root. The hair root rests just below the skin’s surface on the scalp within the hair follicle. New hair growth happens within the follicle. The hair follicle is composed of a hardening protein known as keratin. 

Keratin is the building block of our hair. This protein forms the entire hair shaft, consisting of three layers: the medulla, cortex, and cuticle. 

The medulla is the inner layer of keratin. It features transparent cells. Next is the cortex – it’s where our pigment cells are housed. These are responsible for your hair color. The outermost layer is called the cuticle. It serves a critical role for the hair shaft, protecting it from damage.

Hair Growth and Thyroid Hormone

Whether you realize it or not, the hair on your head is constantly falling out. Hair growth is best described as a revolving door. The phases of hair growth are always in action, with new hair growing and old hair dying and shedding. 

Let’s take a look at the phases of hair growth.

  • Anagen phase – The growth phase of the hair cycle is known as the anagen phase. This growth phase can last for many years. The anagen phase is responsible for about 90 percent of the hair on your head at any given time.
  • Catagen phase – The next phase is known as the catagen phase. This is called the transition phase of hair growth. During the catagen phase of the hair cycle, the hair follicles cease to grow for a time.
  • Telogen phase – The last phase, known as the telogen phase, is considered the resting phase of the hair growth cycle. During the telogen phase, your old hairs are pushed toward the scalp's surface, where they’re shed naturally and replaced.

Studies have shown how thyroid hormones can impact hair follicle function, including hair growth. Thyroid hormone signaling controls the stem cell functioning of hair follicles. 

Low levels of iodine can inhibit this relationship as it can lead to a decrease in thyroid hormones. The result is hair loss and poor hair growth. 

Other Types of Hair Loss

In most cases, iodine deficiency is not the cause of hair loss. In fact, hair thinning and hair loss are quite common for both men and women. Pattern hair loss or baldness (androgenetic alopecia) is typically linked to genetics. It is responsible for the majority of hair loss in men. 

Other reasons for hair loss include:

  • Anagen effluvium, caused by medications, radiation, and infections
  • Telogen effluvium, loss of hair that is caused by extreme stress
  • Alopecia areata, an autoimmune disorder

In addition to iodine, other nutrient deficiencies can also contribute to hair loss. For example, deficiencies in vitamin D, vitamin C, B vitamins, zinc and iron can all cause issues with hair loss. 

The Bottom Line

Our bodies need iodine to keep our thyroid gland functioning smoothly. When we don’t get enough, our thyroid function can suffer which can lead to hair loss and other symptoms.

Thankfully, our Hair + Energy complex contains iodine, derived from our signature type of JSHealth Kelp™, to support hair health and hair growth when dietary intake is inadequate. 


Iodine and thyroid function | PMC

Nutrition: Effects of iodine deficiency | WHO

Iodine Deficiency | American Thyroid Association

What is the structure of hair and how does it grow? | NCBI

How do thyroid hormones affect the hair follicle? | STC

Thyroid hormone signaling controls hair follicle stem cell function | PMC