Home » Plankton Nutrients » Minerals » Symptoms Iodine Deficiency?


Iodine is used by your thyroids to make hormones which support healthy cell development, a well-working metabolism and controls growth (1). The symptoms of an iodine deficiency are very similar to hyperthyroidism (also known as low thyroid hormones).

Iodine is a important mineral to the human body. Since our body is unable to create this mineral itself, we need to get iodine from our foods. Iodine is not commonly found in the foods we eat (except for seafood). Iodine is therefore usually added in bread and salt (iodized salt). Iodine is a mineral that mainly occurs in seafood, fish, seaweed and plankton.

An iodine deficiency can halt a healthy growth and obstruct learning abilities in children. An iodine deficiency in pregnant women may even result in dwarfism. It’s very important to provide your body with enough iodine. 

There are certain groups of people that have a higher risk of creating a iodine deficiency. Those people may benefit from using iodine supplements next to their daily meals. It is, however, important to note that if you suspect you have a shortage of iodine, you should always consult a doctor before taking any supplements.

People with a higher risk of obtaining an iodine deficiency are (2)(3)(4)(5):

- Pregnant woman (also after birth since they are still providing nutrients for their babies when breastfeeding),
- People following a vegetarian or vegan diet.
- People who don’t consume iodized bread and salt.
- People living in areas with little to none iodine in the soil. This includes most European countries, Asia and New-Zealand.

A shortage of iodine can be recognized by the following symptoms. If you experience one of the symptoms, it may be wise to consult a physician.


This is probably the most common symptom of iodine deficiency. The thyroid is located in front of the neck and is shaped like a butterfly. It makes hormones as soon as it receives a signal from the TSH (the thyroid-stimulating hormone) (6). As soon as the blood levels within the TSH rise, the thyroid will then start making hormones using iodine.

When the body is too low in iodine levels, it will be unable to create hormones (6). However, it will keep trying anyway and swell in the process. This swelling is visible and is called a goitre. If a goitre isn’t treated within a few years, this can eventually lead to permanent thyroid damage. Luckily, this goitre can be treated easily by increasing your daily iodine intake.

In short: neck-swellings, also known as goitres, are a common symptom of an iodine deficiency in the body. This happens when the thyroid gland tries to make hormones even though its iodine supply is very low.


If you’re experiencing a dryer and flaky skin than you normally have, this can be a sign of iodine deficiency. Some studies have recently shown that about 77% of all people with low thyroid hormone levels experience dry and flaky skins as a serious symptom (7). Iodine helps the thyroid to regenerate your skin, just like with your hair follicles.

A deficiency in iodine prevents the thyroid hormones from functioning properly, causing them to be unable to regenerate your skin leading to a flaky and dry feeling skin (8). Thyroid hormones also regulate your sweat glands. If you have lower thyroid hormone levels, you usually sweat less, even during intensive exercises (9)(10).

Sweat helps to moisturize the skin, therefore if the body is unable to produce sweat, your skin will become dryer.

In short: iodine causes your body to sweat and, with that, hydrates your skin. Low levels of iodine prevent your skin cells from regenerating causing you to sweat less and obtaining a dry, flaky skin in the process.


Your heart rate stands for the number of times your heart pumps blood per minute. Iodine helps to regulate your heartbeat.Therefore, a high level of iodine will cause your heart to increase its BPM (beats per minute) and low iodine levels drop your heart’s BPM (11)(12). While small changes in your heartbeat are not a big problem, a heart that’s beating too slow due to an iodine deficiency can cause weakness, dizziness, and fatigue (13).

In short: a low iodine level decreases your BPM. This results in feeling weak, dizzy and may even cause fainting.


An issue not many people keep in mind is that an iodine deficiency can affect your ability to learn and remember things (14)(15)(16). This case was supported when a study with a thousand participants found that adults with normal thyroid hormone levels performed better on memory exercises than the adults that had deficient thyroid hormone levels (17). The thyroid is not only good for your physical body, but it also encourages brain development. An iodine deficiency can, therefore, reduce brain development as it lowers the thyroid hormone levels (18). Another study has found that the hippocampus, which is used to process long-term information and memories, is smaller in people with a long-term iodine deficiency (19).

In short: an iodine deficiency causes learning and memory problems that can occur at any age. During the brain development, however, low iodine levels may even affect the development of the brain.


While gaining weight over time can occur at any age and at any time, unnatural fast weight gain can be caused by a deficiency in iodine. The thyroid controls the rate at which your metabolism works and how quickly food is processed and turned into heat and energy (20)(21). A slow metabolism means that fewer calories are being processed when your body is in rest. This will, over time, turn the excess calories into fat rather than heat or energy (20)(21). Adding more iodine to your diet will increase the speed at which your metabolism works. Iodine helps also to lose weight over time.

In short: a low level of iodine causes your metabolism to slow down, storing food as fat reserves rather than burning it for energy and heat. This may eventually lead to weight gain.


Another very common symptom of a deficiency in iodine is the constant feeling of weakness and fatigue. Daily tasks will feel more overwhelming and harder to complete. A study has found that people with an iodine deficiency and low thyroid hormone levels often feel tired, sluggish, and weaker than people with higher thyroid hormone levels (7). Another study found that feeling weak and tired are the most common symptoms of low thyroid hormone levels (22). The thyroid hormones help create energy for the body to use by converting calories. When there is not enough iodine to create those hormones, they will also be unable to convert those calories causing you to feel tired more easily.

In short: your body uses iodine to generate energy. A low level of iodine may cause you to feel sluggish, tired and weak.


As stated before in this article, pregnant women have a higher risk of iodine deficiency than non-pregnant women. Women carrying a child need to consume more nutrients since they need to provide those nutrients for their baby as well. This continues until after the woman has given birth and is finished breastfeeding the child since the child still needs the nutrients through its mothers’ breastmilk (23).

While mothers with an iodine deficiency may experience the regular symptoms of such a deficiency, babies can have their growth stunted and a lack of brain development (2). A severe iodine deficiency may even lead to stillbirth (24).

In short: pregnant and breastfeeding women are at higher risk of iodine deficiency since they need this for both themselves and their baby. Low levels of iodine can cause pregnancy issues, weak health of the baby, and even stillbirths.


Thyroid hormones not only control the growth of children, but also the growth of hair and nail follicles. When the thyroid hormone levels are low, it will be harder for your hair follicles to regenerate. If this keeps up for a longer period, this may result in hair loss and brittle nails (25). This may also be the reason that people with an iodine deficiency often experience hair loss (26). A study found that about 30% of its participants (700 people) experienced hair loss when diagnosed with low thyroid hormone levels (27).

However, other studies concluded that only people with a history of hair loss in their families experience hair loss when confronted with lower thyroid hormone levels (25).

In short: a shortage of iodine prevents hair follicles from regenerating, causing hair loss in the long term. However, increasing your iodine intake to healthy levels will help to stabilize your hair growth again.


Iodine is used to create thyroid hormones, and a deficiency in iodine will cause your hormone levels to drop down. Since these hormones are used to control your metabolism, a lower metabolism causes your energy and heat levels as well. This is why some people with an iodine deficiency feel cold and have colder limbs than people without this deficiency (28)(29).

Studies have found that over 80% of people are sensitive to cold temperatures when diagnosed with low thyroid hormones (7). Your thyroid hormones also help to activate the production and working of brown fat. Brown fat is a type of “healthy” fat which generates heat for the body as its burned.

Low iodine levels causing problems with the thyroid hormone levels prevent the brown fat from generating heat, causing the body to feel cold (30)(31).

In short: iodine not only creates energy, but also heat. Low levels of iodine causes your temperature to drop, which results in you being more sensitive to cold weather and climates.


When you experience heavy and irregular periods, this may be a sign of an iodine deficiency (32). A study found that 68% of women with low thyroid hormone levels experienced heavier and more irregular periods. Compared to 12% of women with normal thyroid hormone levels (33). As mentioned earlier in this article, iodine helps to regulate the thyroid hormones. Lower thyroid hormone levels can be caused by an iodine deficiency.

Low thyroid hormone levels obstruct the regular hormone signals used to regulate the menstruation and menstrual cycle (34)(35). As a result, women with low thyroid hormone levels will experience heavier and irregular periods.

In short: low thyroid hormone levels interfere with the hormones used during the menstrual cycle. A low iodine deficiency can therefore cause heavier and more irregular periods to occur.