Hashimoto’s: More Than Just a Thyroid Issue
- Ola Krawczyk, Clinical Nutritionist
- Dec 2, 2025
- 6 min read
Updated: 6 days ago
Written by Ola Krawczyk, Clinical Nutritionist
Published: 2 December 2025 | Last reviewed: 2 September 2026
Hashimoto’s thyroiditis is commonly discussed as an underactive-thyroid condition. However, it is important to understand that Hashimoto’s is first an autoimmune thyroid disease, which may gradually lead to hypothyroidism.
In Hashimoto’s, the immune system produces antibodies associated with inflammation and damage to thyroid tissue. The two antibodies most commonly measured are:
Thyroid peroxidase antibodies, or TPOAb
Thyroglobulin antibodies, or TgAb
Over time, this autoimmune process can make it increasingly difficult for the thyroid gland to produce enough thyroid hormone.
However, not everyone with thyroid antibodies immediately develops hypothyroidism. Some people have positive antibodies while their thyroid hormone levels remain within the laboratory reference range. Others gradually develop changes in thyroid-stimulating hormone, or TSH, and free thyroxine, or FT4.
The American Thyroid Association explains that Hashimoto’s often progresses slowly and may cause no symptoms in its early stages, even when thyroid antibodies are present. American Thyroid Association: Hashimoto’s thyroiditis
Expert perspective from Ola Krawczyk: “Hashimoto’s should not be treated as simply a list of foods to avoid. Effective support involves understanding thyroid function, medication, nutritional status, digestive health, symptoms and the person’s broader medical history. The goal is not to promise a cure, but to provide safe, realistic and personalised support.” — Ola Krawczyk, Clinical Nutritionist and accredited ATMS member
What does the thyroid control?
Thyroid hormones influence many important functions, including:
Energy and metabolism
Body temperature
Heart rate
Bowel function
Brain and nervous-system function
Muscle health
Menstrual health
Cholesterol metabolism
This helps explain why Hashimoto’s can feel like a whole-body condition rather than only a thyroid problem.
Common symptoms of Hashimoto’s
Hashimoto’s often develops slowly. Some people have thyroid antibodies before they experience symptoms or develop hypothyroidism.
Possible symptoms include:
Fatigue
Feeling unusually cold
Constipation
Dry skin
Hair thinning
Brain fog
Low mood
Muscle weakness
Menstrual changes
Difficulty managing weight
Elevated cholesterol
Neck fullness or an enlarged thyroid
These symptoms are not exclusive to Hashimoto’s. Iron deficiency, low vitamin B12, poor sleep, perimenopause and other health concerns may feel very similar.
Persistent symptoms therefore deserve a broader assessment rather than being automatically blamed on the thyroid.
How is Hashimoto’s diagnosed?
A medical assessment may include:
TSH
Free T4
TPO antibodies
Thyroglobulin antibodies
Thyroid examination
Thyroid ultrasound when appropriate
Thyroid antibodies help identify autoimmune thyroid disease, while TSH and free T4 help assess how well the thyroid is functioning.
If Hashimoto’s has caused hypothyroidism, levothyroxine is the standard medical treatment. Nutrition support may complement your medical care, but it does not replace medication.
The American Thyroid Association explains that Hashimoto’s may progress slowly over many years and can initially be present without obvious symptoms. Read the American Thyroid Association overview
Why does Hashimoto’s develop?
There is rarely one simple cause.
Hashimoto’s appears to develop through an interaction between genetic susceptibility, immune regulation and environmental influences.
Potential factors include:
Family history of thyroid or autoimmune disease
Female sex
Other autoimmune conditions
Pregnancy and postpartum immune changes
Excessive iodine exposure in susceptible people
Certain medications
Radiation exposure
Possible environmental or infectious influences
Stress, diet and digestive health may influence symptoms and wellbeing, but they should not be presented as the sole causes of Hashimoto’s.
Most importantly, developing Hashimoto’s is not the person’s fault.
The gut–thyroid connection
Digestive health can affect nutrient absorption, bowel regularity, thyroid-medication absorption and general wellbeing.
People with Hashimoto’s may also experience:
Constipation
Bloating
Reflux
IBS
Coeliac disease
Autoimmune gastritis
Iron or vitamin B12 deficiency
SIBO or intestinal methanogen overgrowth
However, Hashimoto’s does not automatically mean someone has SIBO, “leaky gut” or a microbiome imbalance. Digestive symptoms should be assessed individually.
For example, hypothyroidism itself may slow intestinal movement and contribute to constipation and bloating.
A personalised thyroid nutrition assessment may therefore consider:
Thyroid function and medication
Bowel habits
Iron and vitamin B12 status
Coeliac screening
Dietary fibre and fluid intake
Digestive symptoms
Other possible health conditions
Does everyone with Hashimoto’s need to avoid gluten?
No.
A strict gluten-free diet is essential for someone with diagnosed coeliac disease. However, current evidence does not support automatically recommending a gluten-free diet to everyone with Hashimoto’s.
A 2023 review found some possible changes in thyroid markers following a gluten-free diet, but the studies were small and the evidence was not strong enough to recommend it universally.
A supervised gluten-free trial may be considered when:
Coeliac disease has been confirmed
Gluten or wheat sensitivity is suspected
Significant digestive symptoms are present
The trial has a clear purpose and review plan
If coeliac disease is suspected, speak with your doctor before removing gluten. Coeliac testing is most accurate while gluten is still being consumed.
Important nutrients for thyroid health
Several nutrients support normal thyroid hormone production and metabolism.
Selenium
Selenium supports thyroid hormone metabolism and antioxidant protection.
A 2024 analysis of 35 studies found that supplementation was associated with modest reductions in TSH and TPO antibodies in some groups. However, it did not significantly change free T3, free T4, thyroglobulin antibodies or thyroid size. Read the selenium research
Selenium should not be taken automatically because excessive intake may be harmful.
Iron
Iron is needed for normal thyroid hormone production. Iron deficiency can also cause fatigue, hair loss and brain fog—symptoms that can resemble hypothyroidism.
Iron supplements can interfere with levothyroxine absorption and should normally be taken separately according to medical or pharmacy advice.
Read more: Low Iron and Thyroid Health
Vitamin B12 and folate
Low vitamin B12 or folate may contribute to fatigue, weakness and cognitive changes. Risk may be greater when Hashimoto’s occurs alongside coeliac disease, autoimmune gastritis or another cause of poor absorption.
Vitamin D, zinc and magnesium
These nutrients support normal immune, metabolic and thyroid-related processes. Deficiencies should be identified and corrected, but high-dose supplements do not cure Hashimoto’s.
Is there a specific Hashimoto’s diet?
There is no single diet that works for everyone with Hashimoto’s.
A supportive eating pattern may include:
Adequate protein
A variety of vegetables and fruit
Suitable sources of fibre
Omega-3-rich foods
Iron, zinc and selenium from food
Whole-food carbohydrates
Healthy fats
Regular, balanced meals
Adequate hydration
Nutrition should be personalised around the person’s symptoms, pathology, medication, digestive health, food preferences and other conditions.
The goal is to improve nutritional adequacy—not to create fear around food or remove multiple food groups unnecessarily.
Why can symptoms continue when thyroid results are normal?
If fatigue, brain fog, weight changes or digestive symptoms continue despite medically well-managed thyroid levels, other possible contributors should be considered.
These may include:
Iron deficiency
Low vitamin B12 or folate
Coeliac disease
Poor sleep or sleep apnoea
Perimenopause
Insulin resistance
Depression or anxiety
Medication interactions
Inadequate nutrition
Another digestive or medical condition
Persistent symptoms should not automatically lead to more supplements or a more restrictive diet.
The bottom line
Hashimoto’s is an autoimmune thyroid condition that may eventually reduce thyroid hormone production.
Medical treatment and monitoring remain essential. Personalised nutrition may provide additional support by helping to:
Identify nutrient deficiencies
Improve dietary quality
Support bowel regularity
Investigate relevant digestive symptoms
Reduce food and supplement interactions with medication
Support energy and general wellbeing
The aim is not to promise a cure or chase a perfect antibody result. It is to understand your individual health picture and create a safe, realistic plan.
Looking for personalised thyroid nutrition support?
If you have Hashimoto’s, hypothyroidism or ongoing symptoms following thyroid surgery, I can help you review your diet, symptoms, relevant pathology, digestive health and nutritional needs.
I provide evidence-informed thyroid nutrition consultations in Sydney and online across Australia.
This article is for educational purposes only and does not replace medical diagnosis, treatment or advice. Do not change thyroid medication, remove gluten before coeliac testing or begin high-dose supplements without appropriate professional guidance.
About the author
Ola Krawczyk is a Polish-Australian Clinical Nutritionist and accredited ATMS member specialising in thyroid health, gut health, SIBO, microbiome interpretation and perimenopause nutrition.
Her professional approach is also informed by her personal experience with thyroid cancer, thyroid removal, hormonal health challenges and SIBO. Ola provides personalised online nutrition consultations across Australia through Clinical Nutrition by Ola.
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