Key nutrients drive thyroid hormone production. Because the thyroid gland is highly nutrient-dependent, poor nutritional status may contribute to thyroid dysfunction or worsen symptoms.
While specific foods and supplements can't treat or reverse thyroid disease, thyroid supplements and a thyroid-friendly diet can support your treatment.
So, how to know which supplements can benefit your health? How do you know how much to take? How do you know you are getting a quality supplement? Can you cause yourself harm?
The world of supplements may feel overwhelming, and many options are more hype than science. It can be tough to decide if you need a thyroid supplement and what that supplement should contain.
The Food and Drug Administration (FDA) regulates dietary ingredients and dietary supplements. The FDA's regulation of supplements bases itself on the Dietary Supplement Health and Education Act of 1994 (DSHEA). The definition of a dietary ingredient is a vitamin, minerals, herb, amino acid, or any other substance naturally found in foods that can supplement the diet by increasing intake. Supplement makers cannot make any claims regarding their supplement's ability to "treat, diagnose, prevent or cure any disease."
Under DSHEA, the company manufacturing any dietary supplement takes on ensuring that the product is safe before marketing. The FDA is responsible for monitoring post-market supplement safety. The FDA can remove any supplement found to be unsafe—but that may only be after complaints or serious safety issues have been noticed. Of course, this means that there are products on the market that may be unsafe or ineffective.
To ensure that the products you buy are safe and effective, make sure you:
- Inquire with your healthcare provider to ensure a supplement does not interfere with any medications or therapies you are currently taking.
- Buy only from reputable and well-established companies. You can find a lot of information about a company through an online search. Quality control and current "Good Manufacturing Practice" (cGMP) may make quality supplements a bit more expensive. That safety measure is essential for your health and well-being!
- Read the labels—use this chart to determine if you are getting too much (above the Upper Limit (UL)) or the Recommended Daily Allowances (RDAs). Account for any other supplements you are taking.
- Confirm that a supplement has one of these three seals of approval:
- NSF International is an independent non-profit group that certifies supplements and ingredients
- The United States Pharmacopeia Convention (USP) is another independent, non-profit organization that analyzes and sets high standards for medicines, food ingredients, and dietary supplements.
- Check out supplements with Consumer Labs or LabDoor, another independent testing lab.
Types of thyroid support supplements
The thyroid uses iodine to make the thyroid hormones. The numbers associated with thyroxine (T4) and triiodothyronine (T3) represent the number of iodine atoms attached to each. If you don't have enough iodine, you can't make thyroid hormone. The body does not make iodine so this is obtained via the diet.
Many years ago, iodine was added to salt (iodized salt) to ensure everyone got enough iodine. Even if you limit your salt intake, there are other great sources that most people get their iodine source. Fish, dairy products, poultry, eggs, kelp, and other seaweeds are excellent sources of iodine.
The RDA for iodine in adults is 150mcg while the UL is 1,100 mcg. Because excess iodine may cause hypothyroidism, hyperthyroidism and enlarged thyroid, please consult with your healthcare provider regarding whether you need additional iodine for your thyroid health. If iodine supplementation is recommended, it is usually supplied as either potassium iodide (KI), as about 96% of the iodine is absorbed. Iodine is probably best usually supplied as either potassium iodide (KI), as about 96% of the iodine is absorbed.
Selenium supports thyroid hormone synthesis. The thyroid gland primarily makes the inactive hormone T4, but our tissues can only use the active hormone T3. These tissues include the brain, bones, kidney, mitochondria, muscles, skin, heart, hair, gut, and liver. So, T4 needs to convert into T3 in our tissues. This conversion from T4 to T3 requires an enzyme that requires selenium.
Although the Recommended Dietary Allowance (RDA) for selenium is 55 micrograms (mcg) per day, research suggests that higher intake may support optimal health, particularly in patients with Hashimoto's. Aim for ~200 mcg daily from food and/or supplements, as this may help reduce thyroid peroxidase antibodies and improve symptoms associated with the condition.
Selenium is found naturally in many foods such as grains, meat, poultry, fish, and eggs. Still, amounts depend on the selenium concentration of soil and water. Selenium is also available in many multivitamins or as a stand-alone supplement. Look for supplements containing selenomethionine, which absorbs better than other forms like selenite and selenate.
Zinc fights free radical damage, helps prevent poor concentration, and assists in hormone production. This mineral helps with the efficient conversion of T4 to T3. You need enough zinc to convert T4 to the active T3, and you need enough thyroid hormones to absorb enough zinc.
The RDA for adults is 11 mg for men and 9 mg for women. The UL is 40mg for both. Good food sources of zinc include shellfish, meat, nuts, lentils, and other legumes like peas and beans. While the "best" form of zinc is still up for debate, zinc picolinate, gluconate, or acetate rank near the top.
Many minerals are better absorbed in a chelated (linked) form. These minerals say "chelated" in the description or have glycinate, picolinate, acetate, citrate, gluconate, or "___ate" in the name.
Magnesium is an essential mineral that helps our bodies by keeping our bones healthy, regulating blood pressure, calming the nervous system, and increasing energy. It is also critical that magnesium is present for thyroid hormones T4 to convert to T3.
Not only are most people deficient in magnesium, but caffeine can also cause magnesium loss. Many hypothyroid patients have extreme fatigue, making an exhausted body turn to coffee for a quick pick-me-up. So begins a vicious cycle because as we increase caffeine intake, magnesium is lost. Excellent magnesium sources include dark leafy greens, almonds, sunflower seeds, black beans, and bananas.
Besides being an essential component in building red blood cells, iron is necessary to synthesize thyroid hormones. Iron also plays a role in moving oxygen and creating energy within our body. Beef, chicken, salmon, apricots, white beans, and spinach are all rich sources of iron.
All the B-complex vitamins can play a role in thyroid disease. Low levels of vitamin B12 may lead to anemia, inflammation, or impaired digestion. Supplementing with vitamin B12 could help get your energy back. Good sources of B12 include nuts, animal proteins, and dark leafy greens.
Vitamin C helps maintain proper blood pressure levels, reduces the risk of certain cancers, and helps fight heart disease. Citrus fruits, berries, cherries, and tomatoes are all great choices to boost vitamin C levels.
Vitamin D deficiency is commonly found in those with Hashimoto's disease and is associated with the presence of TPO antibodies. Vitamin D supports immune balance by building resilience against infections and maintaining gut health. The best sources of Vitamin D are through sun exposure and foods like salmon, tuna, mackerel, liver, eggs, and fortified foods.
Probiotics are combinations of beneficial bacteria. These good bacteria exist in the gut to help:
- Digest food
- "Train" the immune system
- Maintain a healthy weight
- Make vitamins
- Aid in absorption
- Maintain healthy cholesterol
- Provide a barrier to infections
- Prevent digestive disorders
Probiotics are recommended for those with autoimmune thyroid disease and support overall health in those with hypothyroidism. Probiotics are in foods like yogurt, kefir, unpasteurized sauerkraut, tempeh, miso, and some cheeses. Sources of prebiotics include garlic, onions, asparagus, bananas, and leeks.
Intestinal permeability (commonly referred to as leaky gut) results from an imbalance of good and bad gut bacteria and can affect autoimmunity. Those with autoimmunity may have lower amounts of Lactobacillus and Bifidus (good bacteria) and higher amounts of E. coli and Proteus (harmful bacteria). The harmful bacteria can become pathogens or microorganisms that can cause disease. Taking probiotics can help reintroduce good gut bacteria to balance out that which is detrimental.
Probiotics are not recommended for critically ill or severely immunocompromised patients, those with a short-bowel syndrome, or for those who have central venous catheters.
Several herbs come from Traditional Chinese Medicine (TCM), Ayurvedic, and Western herbal traditions. These herbs are from a class of botanicals called "adaptogens," which support the thyroid by helping the body respond to stress.
Ashwagandha or Withania somnifera comes from Ayurvedic traditions. Ashwagandha supports the adrenal glands and can reduce high cortisol levels. A recent study indicated that Ashwagandha might boost T4 synthesis and T4-T3 conversion and improve thyroid function in hypothyroidism, increasing T3 and T4 levels and decreasing TSH levels.
Eleutherococcus seniticosus is also known as Siberian ginseng, eleuthero, and Devil's shrub. Eleuthero is used to moderate the stress response and may help relieve fatigue and anxiety. It may also support energy metabolism, liver function, and can help promote restful sleep.
Anti-inflammatory herbs may also be useful for those with Hashimoto's thyroiditis or other autoimmune thyroid disorders. Anti-inflammatory herbs include turmeric, garlic, and ginger. These herbs are suitable for cooking.
A note from Paloma Health
Many nutritional factors play a role in optimizing thyroid function. This information is not intended to diagnose, treat, cure, or prevent any disease. We recommend you work with a thyroid nutritionist to determine your specific nutritional needs to optimize your thyroid health.