Thyroid Antibodies: What’s Next?

What do you do if your thyroid antibodies are high?

This article documents my personal journey after discovering elevated thyroid antibodies, what the science says so far, and what has — and hasn’t — helped me.

I’m a 47-year-old man from the United Kingdom, and in early 2025, I discovered that I have autoimmune thyroid antibodies consistent with Hashimoto’s thyroiditis. My thyroid function is currently normal, but this article explores what can be done at this early stage.

My Diagnosis

In January 2025, I had a blood test through Medichecks and discovered that I had elevated thyroid peroxidase (TPO) and thyroglobulin (Tg) antibodies. These antibodies are associated with autoimmune thyroid disease and are commonly seen in Hashimoto’s disease and Graves’ disease.

At the time, my TSH, free T3, and free T4 were all within the normal reference range. However, the presence of elevated antibodies placed me at increased risk of developing thyroid dysfunction in the future. I was advised to monitor my thyroid function annually.

On the same blood test, I also discovered:

• slightly raised LDL cholesterol

• low serum folate

• low-normal testosterone

Finding Support and First Steps

After receiving my results, I joined the Thyroid UK community on HealthUnlocked: https://healthunlocked.com/thyroiduk

Members explained that elevated antibody levels alone are often sufficient for diagnosing Hashimoto’s thyroiditis, even when thyroid hormone levels remain normal. This was a sobering realisation — my immune system was actively attacking my thyroid.

Several practical recommendations emerged repeatedly:

• Trialling a gluten-free diet

• Optimising micronutrient status

• Using a high-quality B-complex containing folate rather than folic acid

  
  

I was told that many people with Hashimoto’s have MTHFR gene variants, which can impair folic acid metabolism. For this reason, methylated folate is often recommended.

Two B-complex supplements were repeatedly suggested:

• Thorne Basic B

• Igennus B-Complex

  
  

I chose Thorne Basic B, which I ordered from iHerb.

I was also advised to stop B-complex supplements 5–7 days before blood tests, because they contain biotin, which can falsely affect thyroid test results. During that week, I was advised to use a standalone folate supplement such as Jarrow Methylfolate 400 mcg.

Genetics vs Environment

My mother had an overactive thyroid (hyperthyroidism) shortly after giving birth to my sister and me. Thyroid disease often runs in families, and genetics are thought to account for around 70–80% of Hashimoto’s risk, with environmental factors making up the remaining 20%.

That 20% became my focus.

Could diet, lifestyle, and nutrient optimisation influence disease progression?

Early Intervention and Preventive Care

A particularly influential article was published by Thyroid Patients Canada: https://thyroidpatients.ca/2024/10/30/antibody-thyroid-dysfunction-normal-tsh/#1-failure-of-preventive-thyroid-care-in-hashimoto-s

The article argues that many patients miss an opportunity for preventive care during early Hashimoto’s, when thyroid hormone levels are still normal, but antibodies are already causing damage.

I also read Hashimoto’s Protocol by Izabella Wentz, which provided a great deal of practical and conceptual clarity.

At the same time, I began reviewing meta-analyses on PubMed, focusing on interventions with the strongest overall evidence base rather than isolated studies.

Evidence-Based Interventions

Selenium

Selenium is the most extensively studied supplement in Hashimoto’s.

The most recent meta-analysis (2025) concluded: https://pubmed.ncbi.nlm.nih.gov/40898469/

Selenium supplementation helps reduce TPO antibody and TSH levels, with selenomethionine being more effective than sodium selenite or selenium yeast.

The most commonly studied dose is 200 mcg/day.

I supplemented with selenium but did not see a meaningful change in my antibody levels or thyroid hormones. Before diagnosis, I had already been eating Brazil nuts daily, which are rich in selenium, so it’s possible I was not deficient. Selenium appears to work best when correcting a deficiency.

My current view:

• Trial 200 mcg selenomethionine for 3–6 months

• reassess

• Consider switching to 1–2 Brazil nuts daily long-term

  Excess selenium intake carries risks, so food-based sources may be safer over time.

Vitamin D

Before my diagnosis, I was already supplementing 75 mcg (3,000 IU) vitamin D3 daily, which kept my blood levels between 100–125 nmol/L (40–50 ng/mL) year-round.

The latest meta-analysis found that vitamin D supplementation reduced TPOAb and TgAb levels, particularly in individuals who were deficient or insufficient at baseline: https://pubmed.ncbi.nlm.nih.gov/40538736/

If deficient, adjusting intake to achieve blood levels of 100–125 nmol/L appears reasonable.

Iodine

Iodine is a Goldilocks nutrient in Hashimoto’s — too little or too much can worsen autoimmunity.

Evidence suggests aiming for 100–200 mcg/day from all sources, while avoiding:

• iodine supplements

• seaweed

• excessive iodised salt

• iodine-containing cosmetics and medical products

  
  

Two key meta-analyses illustrate this risk clearly:

• https://pubmed.ncbi.nlm.nih.gov/31713113/

• https://pubmed.ncbi.nlm.nih.gov/28640139/

Iron

Iron is essential for thyroid hormone synthesis.

As a middle-aged man who does not menstruate, my ferritin levels have always been adequate on a nutrient-dense diet. However, this is a nutrient that must be tested, not assumed.

Meta-analyses show associations between iron deficiency, thyroid dysfunction, and autoimmunity:

• https://pubmed.ncbi.nlm.nih.gov/39944206/

• https://pubmed.ncbi.nlm.nih.gov/38004184/

Gluten-Free Diet

A gluten-free diet is often recommended for Hashimoto’s.

After adopting a gluten-free diet:

• thyroglobulin antibodies fell from 148 → 93.3 kIU/L

• hs-CRP fell from 0.73 → 0.31 mg/L

• TPO antibodies and thyroid hormones remained largely unchanged

  
  

Medichecks class Tg antibodies as positive above 115, so this reduction felt clinically meaningful.

The latest meta-analysis found mixed results: https://pubmed.ncbi.nlm.nih.gov/41228508/

Gluten-free diets reduced anti-Tg antibodies but increased anti-TPO antibodies, with very low certainty of evidence.

My conclusion is that gluten-free diets may work best if:

• You are coeliac or gluten-sensitive

• Tg antibodies are elevated

• Systemic inflammation is present

  
  

For this reason, I have continued eating gluten-free.

Exercise

I exercise daily, including:

• walking

• cycling

• strength training

  
  

The latest meta-analysis suggests that alternating aerobic and resistance training is optimal: https://pubmed.ncbi.nlm.nih.gov/40446861/

That said, any regular movement appears beneficial.

Where I Am Now (January 2026)

Over the past year, I have:

• Reduced thyroglobulin antibodies

• lowered systemic inflammation

• corrected a folate deficiency

  
  

My current TSH is 2.74, and I would like to bring this below 2.0 during 2027, if possible.

I currently have blood tests every two months.

Testing

At present, I use the Medichecks Advanced Thyroid Function Blood Test: https://www.medichecks.com/products/advanced-thyroid-function-blood-test

A 10% discount is available via Thyroid UK: https://thyroiduk.org/testing/private-thyroid-tests-in-the-uk/medichecks-2/

Supplements & Diet (Current)

Supplements:

• Vitamin D3 – 75 mcg (3,000 IU)

• Thorne Basic B-Complex

• Magnesium glycinate – 200 mg (evening)

• Vitamin B6 – 100 mg (primarily for anxiety)

• Arginine & citrulline (for exercise)

• Experimental: pycnogenol (100 mg) and myo-inositol (4 g)

In 2026, I also experimented with:

• selenomethionine

• myo-inositol

• ashwagandha

• Nigella sativa powder

  
  

None produced a meaningful effect on antibodies or thyroid hormones.

Diet:

A whole-foods, gluten-free diet including:

• dairy, eggs, meat

• fruit and vegetables

• oysters, tuna

• Brazil nuts

• potatoes, rice, honey

Ongoing Experiments

I am currently experimenting with a Bon Charge Mini Red Light Therapy Device, using near-infrared 850 nm light over the thyroid:

• 20 minutes

• three times per week

  
  

I will post the results of this experiment on this website.

Potential future experiments include:

• Prunella vulgaris

• acupuncture

• probiotics

Final Thoughts

Hashimoto’s does not begin with hormone failure — it begins with antibodies.

If we wait for TSH to rise, we may miss an opportunity for early intervention.

I will continue documenting what works, what doesn’t, and what the evidence actually shows.

I hope you have a healthy and curious 2026.