Support your Thyroid

Minerals

Iodine -- Iodine remains the major nutrient required for functioning of the thyroid gland. Main dietary sources: iodized salt, seaweed, dairy, seafood. Note: both deficiency and excess can be harmful.

Selenium -- Three selenium-dependent iodothyronine deiodinases (types I, II, and III) activate and inactivate thyroid hormones, making selenium essential for normal development, growth, and metabolism. Selenium also protects the thyroid from free radical damage via selenocysteine-containing enzymes. Sources: Brazil nuts (highly concentrated), tuna, sardines, eggs. Supplementation at 200 mcg/day has shown reductions in TPO antibody titers in Hashimoto's.

Zinc -- Zinc has potential clinical benefit in autoimmune hypothyroidism and plays a crucial role in thyroid pathophysiology. Sources: oysters, beef, pumpkin seeds, legumes.

Iron -- Iron deficiency can exacerbate the effects of iodine deficiency. Iron is required for thyroid peroxidase function. Sources: red meat, spinach, lentils.

Magnesium -- A balanced level of magnesium, through diet or supplementation, may be beneficial for supporting thyroid health and overall well-being. Sources: leafy greens, nuts, seeds, whole grains.

Vitamins

Vitamin D -- Deficiency is strongly associated with autoimmune thyroid disease (Hashimoto's, Graves'). Supplementation is frequently recommended when levels are low. Evaluation of micronutrients on thyroid functioning has historically been limited to iodine, selenium, vitamin D, and zinc.

Vitamin A -- Vitamin A deficiency correlates with reduced iodine uptake and impaired iodothyronine coupling in the thyroid. Sources: liver, sweet potato, carrots, leafy greens.

Vitamin B12 -- A meta-analysis of 64 studies found an overall reduction of B12 levels in patients with hypothyroidism, with 25% exhibiting B12 deficiency. Autoimmune thyroid disease and pernicious anemia frequently co-occur. Sourcs: meat, dairy, eggs; supplementation often needed in hypothyroid patients.

Supplements / Nutraceuticals

Key nutraceuticals with roles in clinical thyroidology include selenium, L-carnitine, myo-inositol, melatonin, and resveratrol -- some of which have antioxidant properties.

Myo-inositol -- A multicenter study found that myo-inositol (600 mg) combined with selenium (63 mcg) over 6 months resulted in significant reduction of TSH levels, cholesterol, and autoimmunity index in women with subclinical hypothyroidism.

L-carnitine -- Some evidence for benefit in hypothyroid symptom relief, though mostly case-based data.

Foods to Emphasize / Caution

• Supportive: Seafood, Brazil nuts (1-2/day for selenium), eggs, dairy, leafy greens, legumes, colorful vegetables

• Goitrogens (raw cruciferous vegetables): Can inhibit iodine uptake in large amounts when raw -- cooking largely neutralizes this effect; generally not a concern in iodine-sufficient individuals

• Substances introduced with food, such as thiocyanate and isoflavones, or certain herbal preparations, can interfere with micronutrients and influence thyroid function. (relevant for heavy soy consumers or tobacco users)

References (7)

1. 1.

   Benvenga S, Feldt-Rasmussen U, Bonofiglio D, Asamoah E. Nutraceutical Supplements in the Thyroid Setting: Health Benefits beyond Basic Nutrition. Nutrients. 2019;11(9):2214. doi:10.3390/nu11092214.

2. 2.

   Triggiani V, Tafaro E, Giagulli VA, et al. Role of iodine, selenium and other micronutrients in thyroid function and disorders. Endocr Metab Immune Disord Drug Targets. 2009;9(3):277–294. doi:10.2174/187153009789044392.

3. 3.

   Khan SZA, Lungba RM, Ajibawo-Aganbi U, et al. Minerals: An Untapped Remedy for Autoimmune Hypothyroidism?. Cureus. 2020;doi:10.7759/cureus.11008.

4. 4.

   Shulhai AM, Rotondo R, Petraroli M, et al. The Role of Nutrition on Thyroid Function. Nutrients. 2024;16(15):2496. doi:10.3390/nu16152496.

5. 5.

   Krishnamurthy HK, Reddy S, Jayaraman V, et al. Effect of Micronutrients on Thyroid Parameters. Journal of Thyroid Research. 2021;2021:1–8. doi:10.1155/2021/1865483.

6. 6.

   Unfer V, Koch CA, Benvenga S, Leung AM. Editorial: Dietary supplements for preserving thyroid health: the scientific evidence-based view. Frontiers in Endocrinology. 2023;14. doi:10.3389/fendo.2023.1213082.

7. 7.

   Benvenga S, Feldt-Rasmussen U, Bonofiglio D, Asamoah E. Nutraceutical Supplements in the Thyroid Setting: Health Benefits beyond Basic Nutrition. Nutrients. 2019;11(9):2214. doi:10.3390/nu11092214.