Hypothyroidism: Symptoms, Nutrition & Supplements for Thyroid Health
Disclaimer: This blog is for educational purposes only and is not medical advice. Always consult a qualified healthcare practitioner for personalised guidance.
Feeling constantly tired, struggling with your weight, experiencing constipation or feeling unusually cold? These can be signs of hypothyroidism, also known as an underactive thyroid.
Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone. Thyroid hormones play an important role throughout the body, including energy metabolism, body temperature, heart function, digestion and brain function.
For many women, thyroid health can also intersect with menstrual cycles, fertility, pregnancy, mood, digestion and metabolic health.
What is hypothyroidism?
The thyroid is a small, butterfly-shaped gland located at the front of your neck. It produces thyroid hormones, primarily thyroxine (T4), which helps regulate how your body uses energy.
Hypothyroidism occurs when the thyroid does not produce enough thyroid hormone for the body's needs.
One of the most common causes of hypothyroidism in Australia is Hashimoto's disease, an autoimmune condition in which the immune system attacks the thyroid gland. Other causes can include thyroid surgery, certain medications, radiation treatment and insufficient iodine intake.
Hypothyroidism can develop gradually, and symptoms can sometimes be mistaken for stress, poor sleep, nutritional deficiencies or simply being busy.
Common symptoms of hypothyroidism
Symptoms vary from person to person and can develop slowly.
Common symptoms of an underactive thyroid include:
Fatigue and low energy
Feeling unusually cold
Unexplained weight gain or difficulty managing weight
Constipation
Dry skin
Thinning or brittle hair
Brittle nails
Brain fog or difficulty concentrating
Low mood
Muscle aches or weakness
A slower heart rate
Irregular or heavier menstrual periods
Difficulty becoming pregnant
These symptoms are not specific to hypothyroidism, which is why appropriate medical assessment and blood testing are important.
How is hypothyroidism diagnosed?
If you are experiencing symptoms that could indicate an underactive thyroid, speak with your healthcare provider.
Thyroid function is assessed through blood tests. TSH (thyroid-stimulating hormone) is commonly used as the initial test, with free T4 (FT4) and free T3 (FT3) helping assess circulating thyroid hormone levels. Thyroid antibody testing (TPO-Ab and Tg,Ab) may also be appropriate when an autoimmune thyroid condition such as Hashimoto's is suspected.
If you have already been diagnosed with hypothyroidism or Hashimoto’s, regular monitoring is important to ensure your treatment remains appropriate.
Hypothyroidism and Hashimoto's thyroiditis
Hashimoto's thyroiditis is an autoimmune condition and is the most common cause of hypothyroidism in Australia.
Hashimoto's can be particularly relevant when considering nutrition because your overall health, dietary pattern, nutrient status, gut health and lifestyle may all form part of a broader individualised approach.
There is currently no single “Hashimoto's diet” that is appropriate for everyone. Instead, nutrition should be personalised to your symptoms, dietary intake, medical history, medications, nutrient status, and individual goals.
Can nutrition and supplements help hypothyroidism?
Certain nutrients are important for thyroid health and thyroid hormone production. While levothyroxine replaces the thyroid hormone that the body is no longer producing adequately, ensuring sufficient levels of key nutrients can provide the building blocks and cofactors required for normal thyroid hormone production and metabolism.
Nutrients such as iodine, selenium, zinc and iron all play important roles in thyroid function. When nutritional deficiencies are present, correcting them may help support healthy thyroid function. Some nutrients, particularly selenium, have also been studied for their potential role in supporting thyroid health and reducing thyroid antibody levels in some people with autoimmune thyroid conditions such as Hashimoto’s thyroiditis. However, responses vary between individuals, and supplementation is not a replacement for medical treatment. In some cases, thyroid hormone medication such as levothyroxine is absolutely indicated and should be taken as prescribed.
This is where working with a qualified clinical nutritionist or naturopath is extremely valuable. An individualised approach considers your diet, nutritional status, symptoms, medications and relevant pathology to determine whether specific nutrients or dietary strategies may be appropriate for you.
It is important to remember that more is not always better when it comes to thyroid nutrients. In particular, excessive iodine supplementation can negatively affect thyroid function. Any supplementation should therefore be tailored to your individual needs and undertaken alongside appropriate medical care.
Important nutrients for thyroid health
The thyroid requires several nutrients to function normally. However, more is not necessarily better, and supplementation should be individualised based on your test results.
Iodine
Iodine is essential for thyroid hormone production. Too little iodine can contribute to hypothyroidism, but excessive iodine can also negatively affect thyroid function. This is particularly important if you have Hashimoto's or another thyroid condition. Avoid automatically adding high-dose iodine or kelp supplements to your routine without professional guidance. Excess iodine can cause thyroid problems, and iodine supplements are not appropriate for everyone with hypothyroidism.
Selenium
Selenium is an essential trace mineral that plays an important role in thyroid health, including supporting thyroid hormone metabolism and the conversion of T4 (thyroxine) to T3 (triiodothyronine), the more biologically active form of thyroid hormone.
Food sources include:
Brazil nuts
Seafood
Eggs
Meat
Poultry
Whole grains
Zinc
Zinc is involved in numerous processes throughout the body and plays an important role in thyroid function, including supporting thyroid hormone metabolism and the conversion of T4 (thyroxine) to T3 (triiodothyronine), the more biologically active form of thyroid hormone.
Food sources include:
Seafood
Meat
Eggs
Dairy
Legumes
Nuts and seeds
Iron
Iron is an essential nutrient involved in many physiological processes and plays an important role in thyroid hormone production and metabolism. Iron is required for the function of thyroid peroxidase (TPO), an enzyme involved in the production of thyroid hormones, and also supports deiodinase enzymes, which are involved in thyroid hormone metabolism and the conversion of T4 to T3.
Food sources include:
Animal sources of iron: lean red meat, chicken, fish, seafood/shellfish.
Vegetarian sources of iron: Eggs, legumes (lentils, chickpeas, black beans, kidney beans, soybeans), nuts, seeds, dark leafy green vegetables - spinach, kale, broccoli, chard. Include a squeeze of lemon to enhance iron absorption.
Should you avoid gluten with Hashimoto’s?
One reason avoiding gluten may be worth considering with Hashimoto’s is that some proteins in gluten share structural similarities with proteins found in thyroid tissue. In susceptible individuals, this may contribute to an immune response where the body can mistake gluten for thyroid tissue, potentially contributing to ongoing inflammation and autoimmune activity.
What about cruciferous vegetables and the thyroid?
You may have heard that goitrogenic foods should be avoided if you have hypothyroidism or Hashimoto’s. Goitrogens are naturally occurring compounds that can interfere with normal thyroid function by blocking the body's ability to use iodine
Goitrogenic foods include cruciferous vegetables such as broccoli, cauliflower, Brussels sprouts, kale, cabbage, turnips, mustard greens and radishes. Other foods containing goitrogenic compounds include soy products, peanuts, pine nuts and millet.
For most people, there is no need to completely avoid these nutritious foods. However, if you have a thyroid condition, it may be preferable to cook goitrogenic foods rather than consuming large amounts of them raw, as cooking can reduce the activity of some goitrogenic compounds.
Thyroid medication and nutrients
If you take levothyroxine, how you take your medication matters.
Certain foods, some medicines and supplements can affect absorption. Your healthcare professional will advise you on the best timing for your specific medication.
Hypothyroidism, periods and fertility
Hypothyroidism can contribute to irregular or heavier menstrual periods and may affect fertility. Untreated hypothyroidism during pregnancy can also increase the risk of pregnancy complications.
If you are trying to conceive, pregnant or planning pregnancy and have thyroid concerns, it's important to work closely with your GP or relevant medical practitioner.
Nutrition can then be considered as part of a broader preconception or pregnancy health plan.
The bottom line
Hypothyroidism is a common condition that occurs when the thyroid gland does not produce enough thyroid hormone.
If you suspect you have an underactive thyroid, the first step is appropriate medical assessment and blood testing.
If you have already been diagnosed with hypothyroidism or Hashimoto’s, nutrition and naturopathy can form part of a broader approach to supporting your health alongside appropriate medical care. A balanced, nutrient-dense diet can help ensure you are meeting your nutritional requirements, while an individualised approach can identify potential nutritional deficiencies, dietary factors and lifestyle considerations that may be relevant to your symptoms and overall wellbeing.
If you're experiencing ongoing symptoms despite having your thyroid medically managed, it may be worth looking beyond the thyroid alone and considering the wider picture of your health. A qualified naturopath and clinical nutritionist can work alongside your medical team to assess your diet, nutritional status, digestive health, lifestyle and relevant pathology, helping to develop an individualised plan to support your energy, metabolism, gut health and overall wellbeing.
Please note: Not all supplements are safe for everyone. Medications, pregnancy, and individual health conditions must be considered before using any supplement, and advice should be tailored to your personal needs by a qualified health practitioner.
★ Take the Next Step ★
Managing thyroid health naturally is possible with the right support tailored to your unique needs. If you’d like personalised guidance, you can book a 1:1 consultation with me today and start your journey to better health.