Your Thyroid Suffers If You Miss These Micronutrients!

Here’s a must-know regarding hypothyroidism: Micronutrients can work “magic”!

Certain nutritional "hacks" can optimize thyroid function! Improving our thyroid health leads to better energy, fat burning, mental health, and balanced levels of sex hormones (estrogen, progesterone, testosterone, etc.).

There's a fantastic article just published in 2024 (The Role of Nutrition on Thyroid Function by Shulhai et al.) that reviews essential thyroid nutrients and highlights human studies showing significant improvements in thyroid function when many of these nutrients are optimized.

Here’s the thyroid all-star team: Selenium, Zinc, Vitamin A, Vitamin D, Iron, & Iodine.

Let’s break it down.

• Selenium
  • Functions (3):
    • Converts inactive T4 into active T3
    • Protects the thyroid from oxidative damage
  • Amount Needed:
    • RDA: 55 mcg/day (16)
    • Add a couple Brazil nuts into your smoothies or salads each week and consume about 3 servings of fish each week to fulfill your quota (1,2).
  • Food Sources (17):
    • Brazil Nuts: 7 nuts = 544 mcg
    • Shrimp: 3.5 oz = 45 mcg
    • Chicken: 3.5 oz = 25 mcg
    • 1 Egg = 15 mcg

• Zinc
  • Functions (3,4):
    • Supports thyroid gene expression, essential for thyroid hormone synthesis
    • Supports thyroid hormone binding
    • Converts “inactive” (T4) to active (T3) thyroid hormone
  • Amount Needed (15):
    • RDA: 8 mg/day
  • Food Sources (15):
    • Oysters: 3 oz = 32 mg
    • Beef: 3.5 oz = 4.8 mg
    • Chicken: 3.5 oz = 4.4 mg
    • Pumpkin Seeds: 1/4 cup = 2.2 mg
    • Almonds: 1/4 cup = 1 mg

• Vitamin A
  • Functions (5):
    • Necessary for T3 to bind to thyroid receptors
    • Regulates TSH levels to ensure thyroid hormone production.
  • Amount Needed:
    • 700 mcg RAE/day (women)
    • 900 mcg RAE/day (men)
  • Food Sources:
    • Beef Liver: 3 oz = 6,582 mcg RAE
    • Sweet Potato (Baked): 1 medium = 1,096 mcg RAE
    • Carrots (Raw): 1/2 cup = 459 mcg RAE
    • Spinach (Cooked): 1/2 cup = 573 mcg RAE
    • Cantaloupe: 1/2 cup = 135 mcg RAE

• Vitamin D
  • Functions (5):
    • Keeps inflammation and immune function in check, making it vital for thyroid health.
    • Keeps thyroid auto-antibodies in check (fights against autoimmune thyroid conditions)
      • Getting vitamin D levels toward the middle part of the acceptable range has been shown to have a significant impact in helping some with thyroid autoimmunity.
  • Amount Needed (15):
    • RDA: 600 IU/day*
      • *Amount of vitamin D needed is highly variable and depends on underlying health conditions, genetics, and current vitamin D levels. Some individuals may require significantly higher doses than the RDA to achieve optimal levels.
  • Sources (15):
    • Salmon: 3.5 oz = 570 IU
    • Sardines: 3.5 oz = 193 IU
    • Egg yolk: 1 large = 41 IU
    • Sunlight: 10 min. midday exposure = 3,000–5,000 IU*
      • *Amount of vitamin D synthesized depends on amount of unclothed, exposed skin, skin type, latitude, season and time of day

• Iron
  • Function (5,6):
    • Needed for Thyroid Peroxidase (TPO) enzyme to synthesize thyroid hormone
    • Keeps thyroid auto-antibody levels in check
      • Restoring low iron levels has been shown to lower thyroid auto-antibodies, and thus improve autoimmune thyroid conditions
  • Amount Needed (15):
    • RDA: 15 mg/day
  • Food Sources (17):
    • Beef: 3.5 oz = 13 mg
    • Spinach: ½ cup cooked = 11 mg

• Iodine
  • Function (9,10):
    • A component of thyroid hormone, thus essential for T3 and T4 formation
  • Amount Needed:
    • RDA: 150 mcg/day (15)
    • Note: Balance is key! Too little or too much has been shown to significantly disrupt thyroid function (9,10)
  • Food Sources (15):
    • Iodized/table salt: 1 tsp = 400 mcg
      • Pink Himalayan, mineral, kosher & sea salts do NOT contain iodine
      • Also note that iodized salt and iodine supplements provide SYNTHETIC forms of iodine.
      • While the practice of iodizing salt has helped the thyroid health of the majority, synthetic iodine may be problematic for some; Synthetic iodine may be structurally distinct, potentially contributing to altered physiological effects and bypassing the gradual release and buffering provided by dietary sources (19).
      • While iodine is essential for thyroid health, research shows that even small amounts of supplemental iodine (e.g., 250 mcg daily) can trigger thyroid dysfunction, including hypothyroidism and hyperthyroidism, in individuals predisposed to autoimmune thyroid conditions (19).
      • The takeaway? Make dietary sources like seafood the preferred choice.
    • Kelp Seaweed: 1 tbsp = 2,000 mcg
    • Wakame Seaweed: 1 tbsp = 120 mcg
    • Cod: 4 oz = 158 mcg
    • Dulse Seaweed: 1 tbsp = 150 mcg
    • Nori Seaweed: 1 sheet = 40 mcg
    • Shrimp: 4 oz = 47 mcg
    • Eggs: 1 large = 24 mcg

How Do You Know If You're Getting Enough of These Key Thyroid Nutrients?

I assess my clients' thyroid nutrient status using a combination of lab testing, food logs, and symptom evaluation. While there isn’t a perfect test for many vitamins and minerals—such as vitamin A, iodine, zinc, or selenium—blood levels can still provide useful insights when interpreted alongside other indicators.

Iron and Vitamin D are among the nutrients more accurately reflected in bloodwork. For instance, low mean corpuscular volume (MCV) or mean corpuscular hemoglobin (MCH), combined with low serum iron or ferritin, suggests iron deficiency.

For zinc, I use indirect methods such as checking fingernails for white spots or markings and reviewing alkaline phosphatase (ALP) levels on bloodwork. Since ALP requires zinc as a cofactor, low levels may indicate insufficient zinc (18), although other factors can also play a role.

To evaluate selenium, I look for poor conversion of T4 to T3 on bloodwork, assess diet for selenium-rich foods (such as fish, eggs, and Brazil nuts), and check for nail abnormalities like white spots.

Vitamin A status is initially gauged through a combination of dietary intake (e.g., brightly colored vegetables, liver, eggs) and functional markers such as vision health.

To assess iodine status, I consider dietary habits such as the type and amount of salt used (iodized vs. non-iodized), seafood consumption frequency, and iodine-containing supplements. While some practitioners use urinary iodine, this tends to be more reflective of recent intake versus overall iodine status (20).

By combining these tools, I develop a well-rounded understanding of nutrient status to guide personalized recommendations.

Want to know what you need to do to optimize your thyroid function? 

>> BOOK A FREE 15 MINUTE CONSULT WITH ME HERE <<

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‍References

1. Shulhai AM, et al. The Role of Nutrition on Thyroid Function. Nutrients. 2024;16(15):2496. doi:10.3390/nu16152496.
2. Redmond GP. Hypothyroidism and men's health. Int J Fertil Womens Med. 2002;47(3):123-127.
3. Zimmermann MB, Köhrle J. The impact of iron and selenium deficiencies on iodine and thyroid metabolism: biochemistry and relevance to public health. Thyroid. 2002;12(10):867-878. doi:10.1089/105072502761016494.
4. Maxwell C, Volpe SL. Effect of zinc supplementation on thyroid hormone function. A case study of two college males. Ann Nutr Metab. 2007;51(2):188-194. doi:10.1159/000103324.
5. Mikulska AA, et al. Metabolic Characteristics of Hypothyroid Patients and the Role of Microelements and Diet in the Disease Management. Int J Mol Sci. 2022;23(12):6580. doi:10.3390/ijms23126580.
6. Abbott RD, et al. Efficacy of the Autoimmune Protocol Diet for Hashimoto's Thyroiditis. Cureus. 2019;11(4). doi:10.7759/cureus.4556.
7. George ES, et al. Practical Dietary Recommendations for the Prevention and Management of Nonalcoholic Fatty Liver Disease in Adults. Adv Nutr. 2018;9(1):30-40. doi:10.1093/advances/nmx007.
8. Renner R. Dietary iodine: why are so many mothers not getting enough? Environ Health Perspect. 2010;118(10). doi:10.1289/ehp.118-2957951.
9. Aghini-Lombardi F, et al. Iodine intake and thyroid function in pregnant women in Italy. J Endocrinol Invest. 2002;25(9):775-780. doi:10.1007/BF03345980.
10. Pearce EN, et al. Iodine, and thyroid function. J Clin Endocrinol Metab. 2016;101(4):843-851. doi:10.1210/jc.2015-2566.
11. Zimmermann MB. Iodine deficiency. Endocr Rev. 2009;30(4):376-408. doi:10.1210/er.2009-0002.
12. Leung AM, et al. Iodine nutrition in pregnant women. Thyroid. 2011;21(12):1433-1441. doi:10.1089/thy.2011.0114.
13. Duntas LH. The role of iodine in the evolution of thyroid disorders. Arch Hellenic Med. 2012;29(4):409-414.
14. Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Iodine, Iron, Selenium, and Zinc. Washington (DC): National Academies Press (US); 2001. Available from: https://www.ncbi.nlm.nih.gov/books/NBK222310/. doi:10.17226/10026.
15. Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. Available from: https://www.ncbi.nlm.nih.gov/books/NBK222310/ doi: 10.17226/10026
16. Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington (DC): National Academies Press (US); 2000. 7, Selenium. Available from: https://www.ncbi.nlm.nih.gov/books/NBK225470/
17. U.S. Department of Agriculture, Agricultural Research Service. https://fdc.nal.usda.gov/https://fdc.nal.usda.gov/, 2019
18. Weismann K, Høyer H. Serum alkaline phosphatase and serum zinc levels in the diagnosis and exclusion of zinc deficiency in man. Am J Clin Nutr. 1985;41(6):1214-1219. doi:10.1093/ajcn/41.6.1214
19. Reinhardt W, Luster M, Rudorff KH, et al. Effect of small doses of iodine on thyroid function in patients with Hashimoto's thyroiditis residing in an area of mild iodine deficiency. Eur J Endocrinol. 1998;139(1):23-28. doi:10.1530/eje.0.1390023
20. Zimmermann MB. Methods to assess iron and iodine status. Br J Nutr. 2008;99 Suppl 3:S2-S9. doi:10.1017/S000711450800679X

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