Almanac A1C

The Thyroid Support Supplement Guide: Science-Based Nutrients to Optimize Your Thyroid Function

Posted

by

A1C Medical Writer 2

Table of Contents
Keywords: , , , , , , , , , , ,
SupplementPropertiesIndicationsDosageContraindicationsSide EffectsSynergistic Combination
Selenium (Selenomethionin)Antioxidant; supports conversion of T4 to T3; reduces TPOAb/autoimmunity. Selenium is a vital trace mineral for thyroid health, primarily because it enables the conversion of inactive hormone T4 to the active hormone T3 and protects thyroid cells from oxidative damage via its incorporation in selenoproteins.Hashimoto’s autoimmune, deficiency80-200 μg/day [1-3]Avoid excess; renal impairmentNausea, GI upsetMyo-inositol, zinc by enhancing TSH receptor sensitivity, reducing thyroid autoantibodies, and supporting thyroid hormone metabolism, leading to more effective regulation of thyroid function and immune balance than selenium alone.
IodineEssential for thyroid hormone synthesis.
Iodine is an essential mineral that enables the thyroid gland to synthesize thyroid hormones (T3 and T4) by being incorporated into the amino acid tyrosine within thyroglobulin through a process catalysed by thyroid peroxidase.		Deficiency, maintenance150 μg/day [4]Overactive thyroid, autoimmune disease, allergies to iodine, excessGoiter, hypothyroidism, GI upset, metallic tasteSelenium, tyrosine by enabling the safe and efficient synthesis of thyroid hormones: iodine is incorporated into tyrosine residues to form the active hormones, while selenium-containing enzymes protect thyroid cells from oxidative stress during this process and help convert T4 to T3.
L-TyrosineAmino acid precursor for thyroid hormones.
L-Tyrosine is a non-essential amino acid that serves as a critical precursor for the synthesis of thyroid hormones as well as neurotransmitters like dopamine, norepinephrine, and epinephrine.		Support low hormone synthesis500-2,000mg/day [5,6]Hyperthyroidism, Grave’s, MAOIs, migraine sufferersNausea, headache, tirednessIodine, selenium by enabling the safe synthesis and activation of thyroid hormones- iodine is incorporated into tyrosine to form T3 and T4, while selenium-dependent enzymes both protect the thyroid from oxidative stress and convert T4 into the active T3 form for optimal hormone function.
AshwagandhaAdaptogen; may normalize TSH/T3/T4, reduce stress.
Ashwagandha is an adaptogenic herb that helps the body manage stress, reduces anxiety, improves sleep, supports cognitive and physical performance, boost immunity and offers anti-inflammatory and antioxidant benefits.		Subclinical hypothyroid [7]600mg/day [7,8]Hyperthyroidism, pregnancy/ lactationTemporary mild GI issuesSelenium, tyrosine, zinc works synergistically with ashwagandha by supporting optimal thyroid hormone production, balancing stress response, and enhancing immune and antioxidant defences,  which together can help regulate metabolism, energy levels and recovery from physical or biochemical stress
Zinc (Glycinate)Cofactor for T4àT3 conversion; supports immune and thyroid function.
Is a highly bioavailable, chelated form of zinc that efficiently supports immune health, enzyme function, skin integrity, wound healing, cellular metabolism, and antioxidant defences, with superior absorption and gastrointestinal tolerability compared to other zinc salts.		Deficiency, hypothyroid, Hashimoto’s15-30mg/day [9,10]Overuse can deplete copperGI upset, copper deficiencySelenium, myo-inositol works synergistically with zinc glycinate to enhance thyroid function, antioxidant defences, immune regulation, and reduction of thyroid autoantibodies; together they optimize hormone synthesis, cellular protection, and inflammatory balance more effectively than any single nutrient alone.
Vitamin A (Retinyl Pamitate)Required for TSH secretion, T4 à T4 conversion.
Is a stable, fat soluble form of vitamin A that supports optimal vision immune function, cellular growth and differentiation and maintains healthy skin and epithelial tissues.		Deficiency, impaired conversion2,500-5,000IU/dayHypervitaminosis, pregnancy cautionOverdose: headache, liver, hypothyroidismZinc, protein with vitamin A by improving vitamin A absorption, transport and utilization in the body- zinc is crucial for vitamin A metabolism and protein enables the creation of retinol binding proteins, together supporting immune function, vision, and cellular health.
Myo-Inositol + SeleniumImmune modulator, reduces TSH and autoantibodies.
They support thyroid health by improving TSH sensitivity, reducing thyroid autoantibody levels, and restoring euthyroid status in patients with autoimmune thyroiditis and subclinical hypothyroidism, while also offering antioxidant and anti-inflammatory benefits.		Autoimmune thyroiditis, subclinical600mg/83μg
2x/day [11,12]		Not for hyperthyroidWell toleratedZinc, selenium works synergistically with myo-inositol +selenium by enhancing thyroid hormone synthesis, stabilizing TSH levels, reducing thyroid autoantibodies, and improving insulin sensitivity and immune regulation, resulting in greater improvements in thyroid and metabolic health than any single nutrient alone.
Active B Complex (B2,B6,B9, B12)B vitamins required for hormone synthesis, utilization, conversion. Active B complex provides essential cofactors for energy production, red cell formation, DNA synthesis, nervous system function, and homocysteine regulation, supporting overall cellular health and metabolism.B-vitamin deficiency, thyroid supportPer label, usually 1x/day [13]Non specific, excess can cause neuropathyMild GI, urine discolorationMagnesium, iron, vitamin A to support energy metabolism, red blood cell production, neurological function, and cellular repair, with each nutrient providing complementary cofactor for enzyme activity and optimal nutrient utilization.
Magnesium GlycinateSupports energy production and nerve function; may help with thyroid symptoms.
Magnesium glycinate is highly absorbable and well-tolerated form of magnesium that supports muscle and nerve function, promotes relaxation and restful sleep, aids blood sugar and blood pressure regulation, and benefits bone health with minimal digestive side effects.		General thyroid support, muscle symptoms200-400mg/daySevere kidney disease, excess intakeDiarrhea, low BPB-complex, Vitamin A works synergistically with magnesium glycinate to enhance energy production, optimize nervous system and muscle function, and support tissue repair by providing essential cofactors for magnesium-dependent cellular processes
Iron Bisglycinate (if deficient)Required for TPO function, hormone synthesis.
Iron bisglycinate is a chelated form of iron that offers superior absorption, effectively increases iron and haemoglobin levels, and is gentler on the digestive system with fewer gastrointestinal side effects compared to traditional iron salts.		Iron deficiency, anemia25-50mg/dayIron overload, hemachromatosisConstipation, dark stools, GI upsetB-complex, Vitamin A works synergistically with iron bisglycinate by promoting optimal red blood cell formation and haemoglobin synthesis, enhancing iron absorption and utilization for efficient oxygen transport and energy production.

Notes

  • Selenium: 80-200 μg/day reduces anti-thyroid antibodies, especially in autoimmune thyroiditis. Synergistic with myo-inositol and zinc. Avoid excessive supplementation [1,2,3,10,12,13]
  • Iodine: ~150 μg/day is a standard dietary requirement; excessive intake may worsen autoimmune thyroid disease. Contraindicated with hyperthyroidism [4,14].
  • L-Tyrosine: Useful for hypothyroidism but should be avoided in hyperthyroidism. Dose range varies- 500-2,000mg is commonly seen in supplement protocols [5,6].
  • Ashwagandha: 600 mg/day shown to help normalize thyroid indices in subclinical hypothyroidism, but may worsen hyperthyroidism [7,8].
  • Zinc: 15-30 mg/day, best combined with selenium or myo-inositol. Zinc deficiency impairs T4 to T3 conversion [9,10].
  • Vitamin A: 2,500-5,000 IU/day; retinyl palmitate supports conversion and may reduce subclinical hypothyroidism, but excessive doses may impair thyroid function [13,15,16].
  • Myo-Inositol +Selenium: 600mg myo-inositol + 83 μg selenium twice daily shown immune-modulatory effect, reduces risk of progressing to overt hypothyroidism [11,12].
  • Active B Complex: Needed for general thyroid support; no direct effect unless deficiency is present [13,17].
  • Magnesium Glycinate: 200-400mg/day supports muscular and nervous function, indirectly benefits thyroid patients.
  • Iron Biglycinate: For deficiency only; 25-50mg/day is typical, required for thyroid peroxidase function.

This table is meant for educational purposes only. Please check proper clinical guidelines and consult your physician before starting any new supplements.

References

  1. Sturniolo G, Mesa J. Selenium supplementation and autoimmune thyroid diseases. Endocrinología y Nutrición. 2013 Oct;60(8):423–6.
  2. Vol 17 Issue 7 p.5-6 | American Thyroid Association [Internet]. American Thyroid Association. 2016. Available from: https://www.thyroid.org/patient-thyroid-information/ct-for-patients/july-2024/vol-17-issue-7-p-5-6/
  3. Ventura M, Melo M, Carrilho F. Selenium and thyroid disease: From pathophysiology to treatment. International Journal of Endocrinology [Internet]. 2017;2017(1):1–9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5307254/
  4. Iodine: Uses, Side Effects, Interactions, Dosage, and Warning [Internet]. Webmd.com. 2011. Available from: https://www.webmd.com/vitamins/ai/ingredientmono-35/iodine
  5. L-Tyrosine Uses, Side Effects & Warnings [Internet]. Drugs.com. Available from: https://www.drugs.com/mtm/l-tyrosine.html
  6. Here’s What You Should Know About L-Tyrosine [Internet]. Verywell Health. Available from: https://www.verywellhealth.com/everything-you-need-to-know-about-l-tyrosine-7567409
  7. Sharma AK, Basu I, Singh S. Efficacy and safety of ashwagandha root extract in subclinical hypothyroid patients: A double-blind, randomized placebo-controlled trial. Journal of alternative and complementary medicine [Internet]. 2018;24(3):243–8. Available from: https://www.ncbi.nlm.nih.gov/pubmed/28829155
  8. Should You Take Ashwagandha for Thyroid Issues? [Internet]. Healthline. 2019. Available from: https://www.healthline.com/nutrition/ashwagandha-thyroid
  9. Wentz DI. How Zinc Deficiency Affects Hashimoto’s – Dr. Izabella Wentz [Internet]. Dr. Izabella Wentz, PharmD. 2022. Available from: https://thyroidpharmacist.com/articles/hashimotos-and-zinc-deficiency/
  10. Maxwell C, Volpe SL. Effect of Zinc Supplementation on Thyroid Hormone Function. Annals of Nutrition and Metabolism. 2007;51(2):188–94.
  11. Myo-inositol and selenium reduce the risk of developing overt hypothyroidism in patients with autoimmune thyroiditis [Internet]. European Review. 2017. Available from: https://www.europeanreview.org/article/12994
  12. Nordio M, Basciani S. Treatment with Myo-Inositol and Selenium Ensures Euthyroidism in Patients with Autoimmune Thyroiditis. International Journal of Endocrinology [Internet]. 2017;2017:1–6. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5331475/
  13. Vitamins and minerals and their importance for the Thyroid [Internet]. Thyroid UK. 2020. Available from: https://thyroiduk.org/role-of-vitamins-and-minerals/
  14. Iodine: Side Effects, Uses, Dosage, Interactions, Warnings [Internet]. RxList. 2021. Available from: https://www.rxlist.com/iodine/generic-drug.htm
  15. Farhangi MA, Keshavarz SA, Eshraghian M, Ostadrahimi A, Saboor-Yaraghi AA. The effect of vitamin A supplementation on thyroid function in premenopausal women. Journal of the American College of Nutrition [Internet]. 2012 Aug 1;31(4):268–74. Available from: https://pubmed.ncbi.nlm.nih.gov/23378454/#:~:text=Vitamin A has been shown
  16. Saleh SR, Zaki R, Hassan R, El-Kersh MA, El-Sayed MM, Alshimaa A Abd Elmoneam. The impact of vitamin A supplementation on thyroid function and insulin sensitivity: implication of deiodinases and phosphoenolpyruvate carboxykinase in male Wistar rats. European Journal of Nutrition. 2022 Jul 9;61(8):4091–105.
  17. Apeland T, Kristensen O, Strandjord RE, Mansoor MA. Thyroid function during B-vitamin supplementation of patients on antiepileptic drugs. Clinical Biochemistry. 2006 Mar;39(3):282–6.