The best-supported supplements for Hashimoto's thyroiditis are selenium (Grade A), vitamin D3 (Grade B), and myo-inositol combined with selenium (Grade B). A 2024 network meta-analysis of 35 randomized controlled trials confirmed that selenium reduces TPO antibody levels at 3 and 6 months. The VITAL trial (2022, NEJM) found vitamin D3 reduced new autoimmune disease incidence by 22%. One supplement to avoid above all others: iodine. Supplemental iodine worsens thyroid autoimmunity in genetically susceptible patients. Discuss all supplementation with your physician before starting.
What Makes Hashimoto's Different from Simple Hypothyroidism
Hashimoto's thyroiditis is an immune disease. Its target is the thyroid.
This distinction matters because levothyroxine (the standard treatment) replaces the hormone the thyroid can no longer produce. It does not reduce the autoimmune attack. TPO antibodies (anti-thyroid peroxidase) and anti-TG antibodies (anti-thyroglobulin) continue rising in many patients on stable medication while the gland sustains progressive damage.
Supplementation becomes relevant here. Several micronutrients are direct cofactors in thyroid hormone synthesis and immune regulation. Deficiencies in selenium, vitamin D, zinc, ferritin, and B12 are nearly universal in Hashimoto's patients, and each deficiency compounds the autoimmune process.
Correcting them does not cure the condition. It removes impediments that perpetuate it.
This guide covers supplements specifically. For the complete natural treatment protocol, including diet, gut healing, advanced interventions, and lab targets, see the Hashimoto's natural treatment guide. For a cross-condition overview of how these supplements compare across all autoimmune diseases, see the evidence-graded supplement guide for autoimmune disease.
How to Read the Evidence Grades
Every supplement in this guide carries a grade, reflecting what the published literature actually shows, not what supplement marketing claims.
Multiple RCTs or meta-analyses
Highest confidence: consistent evidence across large trials
Single RCT or strong clinical data
Good confidence: clinical trial exists with mechanistic support
Preliminary or mechanistic only
Early-stage evidence: promising but not yet confirmed in RCTs
Grade A: The Most Supported Supplements
Selenium [Grade A]
Selenium is the most evidence-supported supplement for Hashimoto's thyroiditis. The thyroid gland contains the highest selenium concentration of any organ in the body. Fifteen or more selenoproteins are active in thyroid tissue, including the deiodinase enzymes that convert T4 to active T3, and glutathione peroxidase, which neutralizes the hydrogen peroxide generated during thyroid hormone synthesis.
The CATALYST trial (Winther et al., 2020) enrolled 472 patients with Hashimoto's on levothyroxine and randomized them to 200 mcg selenium-enriched yeast or placebo for 12 months. TPO antibody levels fell significantly in the selenium group.
Quality of life improvement did not reach statistical significance at 12 months, an important nuance most articles omit. Worth knowing if you are tracking your own results.
A 2024 network meta-analysis in Frontiers in Endocrinology synthesized 35 randomized controlled trials involving more than 1,600 patients. Selenium reduced TPO antibodies at 3 and 6 months, independent of baseline selenium status and independent of whether patients were on levothyroxine. A 2023 meta-analysis found selenomethionine reduced TPO antibodies by 46% at 3 months and 80% at 6 months.
Best form: Selenomethionine (organic, amino acid-bound). Superior bioavailability over inorganic selenite.
Dose: 100–200 mcg/day. Do not exceed 200 mcg without medical supervision. Chronic excess above 400 mcg/day causes selenosis: hair loss, nail brittleness, neurological symptoms. Discuss dose with your physician, particularly if your diet is already selenium-rich.
Levothyroxine interaction: Low risk. Standard precaution: separate by 4 hours.
For the full evidence deep-dive (CATALYST trial interpretation, selenomethionine vs. Brazil nuts, the myo-inositol combination, and safety by patient type), see the selenium for Hashimoto's evidence guide.
Iodine Supplements: Why Most Hashimoto's Patients Should Avoid Them [Grade A: Against]
Iodine is essential for thyroid hormone synthesis. T3 contains three iodine atoms; T4 contains four. Iodine deficiency causes hypothyroidism.
This basic physiology leads many patients to self-supplement. In Hashimoto's, this is a consistent mistake.
Excess iodine produces heavily iodinated thyroglobulin molecules that are more immunogenic. It generates reactive oxygen species that damage thyroid tissue and activate innate immune responses. In people with underlying autoimmune susceptibility, this cascade is reliably harmful.
A prospective clinical study found that even 100 mcg/day supplemental iodine triggered thyroid dysfunction in some participants within four weeks. Among those receiving 2,000 mcg/day, 31% developed thyroid dysfunction. A weekly high-dose iodine group developed four times the Hashimoto's incidence compared to controls.
Dietary iodine from seafood, dairy, and iodized salt provides approximately 150 mcg/day, sufficient for iodine-replete populations. Check supplement labels carefully: many products sold as "thyroid support" contain high iodine doses. If you live in a documented iodine-deficient region, discuss minimum-dose iodine use with your physician alongside concurrent selenium supplementation, which reduces oxidative damage from iodine exposure.
Grade B: Well-Supported with Clinical Data
Vitamin D3 + K2 [Grade B]
Deficiency rates in Hashimoto's patients range from 50% to 90% across published studies. The vitamin D receptor (VDR) is expressed on regulatory T cells, dendritic cells, B cells, and Th17 cells.
The active metabolite 1,25-dihydroxyvitamin D suppresses Th17 differentiation, promotes Treg development, and regulates immune tolerance gene expression. VDR polymorphisms, particularly the FokI variant, are among the most replicated genetic risk factors for Hashimoto's.
The VITAL trial (Manson et al., 2022, NEJM) enrolled 25,871 participants in a randomized, placebo-controlled trial of vitamin D3 at 2,000 IU/day in a factorial design with omega-3. In the vitamin D arm, confirmed autoimmune disease incidence fell with a hazard ratio of 0.78 (95% CI 0.61–0.99): a 22% reduction over 5.3 years. This is the largest randomized trial of vitamin D and autoimmune disease incidence to date.
Multiple meta-analyses specific to thyroid autoimmunity show supplementation reduces TPO and TgAb antibody levels, primarily in euthyroid patients with elevated antibodies and documented vitamin D deficiency. The effect is more modest in patients with overt hypothyroidism already on levothyroxine.
Best form: Vitamin D3 (cholecalciferol) paired with K2 (MK-7 form). K2 directs calcium metabolism to bone rather than soft tissue, which is important with long-term D3 supplementation at higher doses.
Dose: 2,000–4,000 IU/day for maintenance. Repletion of severe deficiency may require 50,000 IU weekly for 8 weeks. Target serum 25-OH vitamin D: 30–50 ng/mL. Check baseline levels and retest at 3 months. Response varies by VDR genotype.
Levothyroxine interaction: None documented. Vitamin D can be taken at the same time as levothyroxine.
Myo-Inositol Combined with Selenium [Grade B]
This combination is the most underreported finding in the Hashimoto's supplement literature. Competitors largely ignore it. The data are compelling.
Myo-inositol is a component of phosphatidylinositol signaling pathways. It enhances TSH receptor sensitivity in thyroid follicular cells and may upregulate selenoprotein expression, a synergistic interaction when combined with selenium.
The Italian RCT by Nordio and Basciani (2021) enrolled 86 Hashimoto's patients with subclinical hypothyroidism (TSH 3–6 mIU/L) and randomized them to myo-inositol 600 mg/day combined with selenomethionine 83 mcg/day versus selenium alone for 6 months. The combination group showed TSH reduction of 31–38%, compared to modest reduction in the selenium-only arm.
Quality of life symptom scores improved 49% (from 4.67 to 2.37 on the MSQ scale). TgAb antibodies fell 51%.
The 2024 Frontiers network meta-analysis confirmed this at population scale: myo-inositol combined with selenium produced significantly greater TSH reduction than selenium monotherapy (standardized mean difference: −1.53; 95% CI −2.99 to −0.08).
Dose: Myo-inositol 600 mg/day combined with selenomethionine 83–200 mcg/day.
Levothyroxine interaction: No direct interaction documented. Discuss with your physician before adding, particularly if TSH is in the subclinical hypothyroid range.
For the complete mechanistic explanation of the TSH signaling pathway, which patient profiles benefit most, and the monitoring protocol, see the myo-inositol for Hashimoto's evidence guide.
Magnesium [Grade B]
Magnesium is a cofactor for more than 300 enzymatic reactions, including all three iodothyronine deiodinase enzymes that convert T4 to active T3. Deficiency is common in Hashimoto's: impaired absorption from autoimmune gastropathy, increased urinary losses from chronic inflammation, and dietary insufficiency during elimination phases all contribute.
An RCT testing zinc, vitamin A, and magnesium co-supplementation over 10 weeks found significant increases in serum free T4 and decreases in hs-CRP versus placebo. Magnesium-specific Hashimoto's RCTs remain limited, but the mechanistic rationale and consistent observational data justify a Grade B classification.
Best form: Magnesium glycinate or citrate (superior bioavailability; magnesium oxide causes GI distress and absorbs poorly). Magnesium malate for patients with fatigue and muscle pain.
Dose: 200–400 mg/day. Many patients take it at bedtime. Magnesium modulates GABA receptors and measurably improves sleep quality.
Levothyroxine interaction: Critical. Magnesium chelates levothyroxine in the intestinal lumen, reducing absorption. Separate from levothyroxine by at least 4 hours.
Zinc [Grade B]
Zinc is a cofactor for thyroid peroxidase (the enzyme targeted by TPO antibodies) and for all three deiodinase enzymes. It is required for Treg development, intestinal barrier integrity, and suppression of Th1 and Th17 immune responses.
Serum zinc levels show inverse correlation with TPO antibody titers in multiple published studies. Approximately 30% of Hashimoto's patients have documented deficiency, driven by thyroid hormone effects on renal zinc excretion, achlorhydria from autoimmune gastritis, and increased inflammatory utilization.
The co-supplementation RCT referenced above (zinc, vitamin A, and magnesium; 86 patients; 10 weeks) found significant improvements in free T4 and reductions in hs-CRP versus placebo.
Best form: Zinc picolinate (highest bioavailability in comparative studies). Zinc diglycinate is also well-absorbed.
Dose: 15–30 mg elemental zinc/day. Do not exceed 40 mg without monitoring. Above 30 mg, add 2 mg copper/day: high-dose zinc depletes copper stores.
Levothyroxine interaction: Critical. Zinc chelates levothyroxine. Separate by at least 4 hours.
Iron and Ferritin [Grade B: Deficient Patients Only]
Iron is the heme cofactor for thyroid peroxidase and is required for Type 1 deiodinase (peripheral T4-to-T3 conversion). Iron deficiency impairs thyroid hormone production independent of TSH levels: a patient can have a normal TSH and still have suboptimal synthesis due to ferritin deficiency.
A systematic review found that each unit increase in iron status reduces Hashimoto's risk by 43% in reproductive-age women. A separate observational study documented TSH elevation in 7.5% of patients who took ferrous iron concurrently with levothyroxine, due to impaired hormone absorption.
Test before supplementing. Check serum ferritin (optimal range for thyroid function: 50–70+ ng/mL), serum iron, and TIBC. Do not supplement without confirmed deficiency. Excess iron generates reactive oxygen species that worsen autoimmunity.
Best form: Ferrous bisglycinate (gentler on the GI tract than ferrous sulfate; equivalent bioavailability). Take with vitamin C; take on an empty stomach if tolerated.
Dose: 15–30 mg elemental iron/day for deficiency. Reassess ferritin at 3 months.
Levothyroxine interaction: Critical. Iron chelates levothyroxine more aggressively than most supplements. Separate by at least 4 hours.
Vitamin B12 [Grade B: Deficient Patients Only]
Twenty-seven percent of Hashimoto's patients carry anti-parietal cell antibodies, which destroy the cells that produce intrinsic factor, the protein required for B12 absorption in the small intestine. This autoimmune gastritis overlap goes undetected in most patients. Add elimination diet restrictions, associated celiac disease impairing small bowel absorption, and the result is a 27–46% B12 deficiency rate in hypothyroid patients.
A 2023 meta-analysis found that patients with hypothyroidism had significantly lower B12 than healthy controls (mean difference: −60.67 pg/mL; 95% CI −107.31 to −14.03; p=0.01). The clinical problem: B12 deficiency symptoms (fatigue, brain fog, peripheral neuropathy) overlap substantially with hypothyroid symptoms, masking the deficiency for years.
Best form: Methylcobalamin (active form; superior cellular uptake over cyanocobalamin). Patients with confirmed pernicious anemia may require intramuscular injections (1,000 mcg monthly) rather than oral supplementation.
Dose: 500–2,000 mcg/day oral methylcobalamin for active deficiency.
Testing: Serum B12 below 300 pg/mL indicates deficiency. The 300–500 pg/mL range represents functional deficiency. Add methylmalonic acid (MMA) and homocysteine to confirm functional status regardless of serum level.
Levothyroxine interaction: None. Vitamin B12 can be taken at any time.
Grade C: Emerging or Mechanistic Support
Omega-3 Fatty Acids [Grade C]
EPA and DHA are incorporated into immune cell membranes and converted to specialized pro-resolving mediators: lipoxins, resolvins, and protectins that actively resolve inflammation. They reduce TNF-alpha and IL-6, promote Treg differentiation, and suppress autoreactive B cell activity.
The VITAL trial omega-3 arm tested 1,000 mg/day: hazard ratio 0.85 (95% CI 0.67–1.08) for confirmed autoimmune disease. A trend toward benefit, but the result did not reach statistical significance.
The dose was modest relative to the RA literature, which typically uses 2–3 g/day combined EPA+DHA. Higher-dose trials specific to Hashimoto's are lacking.
Best form: Triglyceride form (superior bioavailability over ethyl ester). Minimum 500 mg EPA+DHA per capsule.
Dose: 1,000–3,000 mg combined EPA+DHA daily.
Gluten-Free Diet: Who Actually Benefits [Grade C, conditional]
The gluten-Hashimoto's connection has a mechanistic basis. Gliadin peptides activate intestinal zonulin release (Fasano et al.), increasing intestinal permeability. Partially digested proteins can enter systemic circulation and trigger cross-reactive immune responses against thyroid antigens via molecular mimicry.
The evidence for this mechanism in patients without celiac disease is weaker than the hypothesis implies. A 6-month RCT in 34 euthyroid Hashimoto's women found that a gluten-free diet did not significantly reduce TPO or TgAb antibody levels. Modest observed improvements in nutrient status (particularly vitamin D and selenium) likely reflected a broader dietary shift, not gluten elimination per se.
For patients with confirmed celiac disease alongside Hashimoto's, a well-established overlap linked by shared HLA haplotypes, a gluten-free diet does reduce TPO antibody levels. Test for celiac disease (tissue transglutaminase IgA and IgG) before committing to strict elimination.
Ashwagandha: Why Caution Is Warranted [Grade C, caution]
Ashwagandha (Withania somnifera) is widely sold to Hashimoto's patients as thyroid support. One randomized trial showed normalized thyroid hormones in subclinical hypothyroidism. The concern in Hashimoto's is not thyroid hormone levels. It is immune stimulation.
The withanolide compounds in ashwagandha may stimulate Th1 and Th17 immune responses: the same pathways that drive thyroid tissue destruction in Hashimoto's.
A case report in peer-reviewed medical literature describes a 47-year-old previously healthy man who began ashwagandha supplementation. Within two months he developed fatigue, nocturnal fever, weight loss, and diarrhea.
Labs confirmed thyrotoxicosis (elevated free T3 and T4, suppressed TSH). Thyroid ultrasound showed heterogeneity consistent with painless thyroiditis. All findings resolved within 50 days of stopping ashwagandha.
If you use ashwagandha alongside a Hashimoto's protocol, monitor thyroid function labs every three months and watch for signs of thyrotoxicosis: palpitations, heat intolerance, unexplained weight loss, tremor, insomnia.
The AIP Diet Alongside Supplements
The Autoimmune Protocol (AIP) diet removes grains, legumes, nightshades, dairy, eggs, nuts, seeds, refined oils, alcohol, and food additives during an elimination phase. It emphasizes nutrient density: seafood, organ meats, vegetables, fermented foods, and healthy fats.
Abbott et al. (2019) enrolled 17 women aged 20–45 with diagnosed Hashimoto's in a 10-week AIP coaching program. All eight subscales of the SF-36 quality of life survey improved significantly. The Medical Symptoms Questionnaire score fell from 92 to 29, a 68% reduction in symptom burden. hs-CRP fell 29%. Levothyroxine dosing was kept stable throughout: the improvements occurred independent of medication changes.
What AIP did not do in the Abbott study: significantly change TPO antibody titers or thyroid function tests. This is worth stating accurately. AIP is not an antibody treatment. It is a tool for identifying dietary triggers and reducing systemic inflammation, which makes other interventions including selenium and vitamin D more effective.
For the full AIP food list, both phases (elimination and reintroduction), the cruciferous vegetable question, and practical implementation for Hashimoto's, see the AIP diet for Hashimoto's guide.
Levothyroxine and Supplements: The Timing Rules Most Guides Skip
Hashimoto's Supplement Timing Guide
On Waking (before eating)
With Breakfast
With Dinner / Evening
What blocks levothyroxine absorption
If you take levothyroxine (Synthroid, Tirosint, Unithroid, or generic), supplement timing is not optional. Several minerals bind thyroid hormone in the intestinal lumen, forming insoluble complexes that the body excretes rather than absorbs. Missing this detail can make levothyroxine appear to stop working.
| Substance | Interaction mechanism | Effect if co-administered | Separation required |
|---|---|---|---|
| Calcium (all forms) | Chelation of T4 | 20–25% reduction in levothyroxine absorption | 4 hours |
| Iron (ferrous) | Chelation | TSH elevation in 7.5% of patients | 4 hours |
| Magnesium | Chelation | Reduced T4 bioavailability | 4 hours |
| Zinc | Chelation | Reduced T4 bioavailability | 4 hours |
| Aluminum antacids | Adsorption | Impaired absorption | 4 hours |
| Coffee | Altered gastric pH and motility | ~25% reduction in absorption | 1 hour minimum |
| Proton pump inhibitors | Reduced gastric acid | Impaired T4 tablet dissolution | Consult physician |
Practical protocol: Take levothyroxine first thing in the morning on an empty stomach with a full glass of water. Wait 30–60 minutes before eating. Take all mineral supplements (calcium, iron, magnesium, zinc) with lunch or dinner.
Patients who struggle to maintain consistent separation may benefit from Tirosint, a soft-gel capsule formulation of levothyroxine that is less affected by mineral interactions. Ask your prescribing physician whether it is appropriate for your situation.
How to Prioritize: A Personalized Starting Protocol
Which supplements you need depends on your lab values, disease stage, and medication status. Before adding anything, run these tests:
- 25-OH vitamin D: deficiency below 20 ng/mL; insufficiency 20–30 ng/mL
- Serum ferritin: optimal for thyroid function 50–70+ ng/mL
- Serum zinc: optimal 90–150 mcg/dL
- Serum B12: functional deficiency below 500 pg/mL; add MMA and homocysteine to confirm
- TPO antibodies and anti-TG antibodies: baseline to track autoimmune activity over time
For the full list of optimal lab ranges and what to do with results, see the Hashimoto's lab targets guide.
For most patients, start here: Selenium 200 mcg selenomethionine/day combined with vitamin D3 2,000–4,000 IU plus K2. These two have the strongest evidence base and the lowest risk profile.
Add if deficient: Magnesium glycinate (4-hour separation from levothyroxine), zinc picolinate, methylcobalamin B12, ferrous bisglycinate for documented ferritin deficiency.
Consider if TSH remains in the subclinical range on levothyroxine: Myo-inositol 600 mg/day combined with your selenium dose. Discuss with your prescribing physician before adding.
For the broader protocol context, including diet, gut healing, LDN, fasting mimicking diet, and lab targets, see the complete Hashimoto's natural treatment guide.
Find out which interventions match your specific condition, lab values, and symptom profile. Take the free AutoimmuneFinder quiz. It maps your answers to a tiered, evidence-graded protocol with dosing guidance for each recommendation.
Frequently Asked Questions
What is the most evidence-based supplement for Hashimoto's?
Selenium. A 2024 network meta-analysis of 35 randomized controlled trials found that selenium supplementation significantly reduces TPO antibody levels at 3 and 6 months, independent of baseline selenium status or levothyroxine use. The CATALYST trial (Winther et al., 2020) confirmed TPO antibody reduction with 200 mcg/day selenium-enriched yeast in 472 patients over 12 months.
Can supplements replace levothyroxine in Hashimoto's?
No. Levothyroxine replaces thyroid hormone the gland can no longer produce. No supplement performs this function. What supplements address is the underlying autoimmune process: reducing TPO antibodies, supporting T4-to-T3 conversion, correcting deficiencies that worsen immune dysfunction. Some patients on the myo-inositol and selenium combination have achieved TSH normalization from the subclinical hypothyroid range. This requires physician management and does not substitute for hormone replacement in overt hypothyroidism.
Should I take iodine supplements for Hashimoto's?
Generally, no. Clinical studies show that even 100 mcg/day supplemental iodine triggers thyroid dysfunction in genetically susceptible individuals within weeks. Weekly high-dose iodine caused four times the Hashimoto's incidence compared to controls in one prospective study. Dietary iodine from seafood, dairy, and iodized salt provides sufficient intake in iodine-replete populations. If you live in a region with documented iodine deficiency, discuss minimum-dose supplementation alongside selenium with your physician.
Can I take magnesium and zinc at the same time as my levothyroxine?
No. This is one of the most consequential mistakes Hashimoto's patients make. Both minerals chelate levothyroxine in the intestinal lumen, reducing absorption. Studies document that calcium alone reduces levothyroxine absorption by 20–25%; the same mechanism applies to iron, magnesium, and zinc. Separate all mineral supplements from levothyroxine by at least 4 hours.
Is ashwagandha safe for Hashimoto's?
Approach it with caution. Ashwagandha's withanolide compounds can stimulate the Th1 and Th17 immune pathways that drive Hashimoto's tissue destruction. A documented case report describes a 47-year-old man who developed thyrotoxicosis within two months of starting ashwagandha; all findings resolved 50 days after stopping. If you use it, monitor thyroid function labs every three months and watch for signs of thyrotoxicosis.
How long does it take for selenium to work for Hashimoto's?
Most trials showing meaningful TPO antibody reduction used supplementation periods of 3 to 6 months. A 2023 meta-analysis found selenomethionine reduced TPO antibodies 46% at 3 months and 80% at 6 months. The CATALYST trial measured outcomes at 12 months. For the myo-inositol and selenium combination, TSH stabilization occurred 42% faster than selenium alone. Retest antibodies no earlier than 3 months.
What supplements help specifically with Hashimoto's fatigue?
Hashimoto's fatigue usually has multiple concurrent causes. Ferritin deficiency impairs T4-to-T3 conversion and oxygen transport. Check ferritin before attributing fatigue to thyroid disease alone. Vitamin B12 deficiency, present in 27–46% of Hashimoto's patients via autoimmune gastritis, produces neurological fatigue and brain fog that mimic hypothyroid symptoms. Vitamin D deficiency causes musculoskeletal fatigue and immune dysfunction. Magnesium deficiency impairs mitochondrial ATP synthesis. Address documented deficiencies before adding condition-specific supplements.
Evidence Summary
| Supplement | Evidence Grade | Key Evidence | Dose Range |
|---|---|---|---|
| Selenium | Grade A | CATALYST trial 2020; Frontiers NMA 2024 (35 RCTs, 1,600+ patients) | 100-200 mcg/day selenomethionine |
| Iodine supplements | Grade A — Avoid | Prospective study: 100 mcg/day triggered dysfunction within 4 weeks | Avoid |
| Vitamin D3 + K2 | Grade B | VITAL trial 2022 (NEJM) - 22% autoimmune disease reduction, n=25,871 | 2,000-4,000 IU/day D3 + K2 MK-7 |
| Myo-Inositol + Selenium | Grade B | Nordio & Basciani 2021 RCT - 49% QoL improvement, 51% TgAb reduction | 600 mg myo-inositol + 83-200 mcg Se |
| Magnesium | Grade B | Co-supplementation RCT: increased free T4, reduced hs-CRP | 200-400 mg/day glycinate or citrate |
| Zinc | Grade B | Co-supplementation RCT; inverse TPO correlation in observational studies | 15-30 mg/day picolinate |
| Iron / Ferritin | Grade B — If Deficient | Systematic review: 43% Hashimoto's risk reduction per ferritin unit | 15-30 mg elemental iron |
| Vitamin B12 | Grade B — If Deficient | Meta-analysis: lower B12 vs. healthy controls (p=0.01) | 500-2,000 mcg/day methylcobalamin |
| AIP Diet | Grade B | Abbott et al. 2019: 68% symptom burden reduction, 29% hs-CRP fall | Dietary protocol - elimination phase |
| Omega-3 | Grade C | VITAL trial 2022: trend toward benefit, HR 0.85 (not significant) | 1,000-3,000 mg EPA+DHA |
| Gluten-free diet | Grade C — Conditional | RCT: no TPO benefit in non-celiac Hashimoto's; benefit if celiac co-exists | Dietary protocol - test first |
| Ashwagandha | Grade C — Caution | Case report: thyrotoxicosis within 2 months of supplementation | Approach with caution; monitor labs |
CATALYST trial 2020; Frontiers NMA 2024 (35 RCTs, 1,600+ patients)
100-200 mcg/day selenomethionine
Prospective study: 100 mcg/day triggered dysfunction within 4 weeks
Avoid
VITAL trial 2022 (NEJM) - 22% autoimmune disease reduction, n=25,871
2,000-4,000 IU/day D3 + K2 MK-7
Nordio & Basciani 2021 RCT - 49% QoL improvement, 51% TgAb reduction
600 mg myo-inositol + 83-200 mcg Se
Co-supplementation RCT: increased free T4, reduced hs-CRP
200-400 mg/day glycinate or citrate
Co-supplementation RCT; inverse TPO correlation in observational studies
15-30 mg/day picolinate
Systematic review: 43% Hashimoto's risk reduction per ferritin unit
15-30 mg elemental iron
Meta-analysis: lower B12 vs. healthy controls (p=0.01)
500-2,000 mcg/day methylcobalamin
Abbott et al. 2019: 68% symptom burden reduction, 29% hs-CRP fall
Dietary protocol - elimination phase
VITAL trial 2022: trend toward benefit, HR 0.85 (not significant)
1,000-3,000 mg EPA+DHA
RCT: no TPO benefit in non-celiac Hashimoto's; benefit if celiac co-exists
Dietary protocol - test first
Case report: thyrotoxicosis within 2 months of supplementation
Approach with caution; monitor labs
This article is for educational purposes only and does not constitute medical advice. Hashimoto's thyroiditis is a medical condition requiring professional management. Before starting any supplement, discuss with your physician or endocrinologist, particularly if you take levothyroxine or other prescription medications. Dosing recommendations reflect general ranges from published clinical trials and may not be appropriate for every individual. AutoimmuneFinder does not diagnose, treat, or prescribe.