Diet plays a large role in thyroid function. Even with medication thyroid function can worsen over time if nutrition is not optimized. Proper nutrition and correcting nutrient deficiencies can help prevent this. With thyroid dysfunction, there tend to be deficiencies in important nutrients. This article breaks down the 19 essential nutrients for thyroid health.
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An estimated 20 million people in the United States have some form of thyroid disease. Additionally, as many as 60 percent of these individuals are unaware of their condition.
A thyroid condition paired with poor nutrition can equal big problems. Medication does not get to the root of the problem but only supplies the body with missing thyroid hormones. So nutrition is crucial to help prevent further damage to the thyroid.
Thyroid conditions can also result in poor gut health and starve the body of essential vitamins and minerals. A poor diet can further deplete these nutrients making the thyroid worse off than it was to begin.
Below is a breakdown of the 19 essential nutrients for thyroid health.
Vitamin A
Vitamin A is a fat-soluble vitamin important for vision, immunity, and reproduction health. This vitamin is good for healthy organs like the lungs and kidneys.
There are two forms of vitamin A:
- Preformed vitamin A retinol
- Provitamin A
Preformed vitamin A called retinol, retinal, and retinyl esters. This is the active form of vitamin A. Provitamin A consists of compounds known as carotenoids (beta-carotene). The body needs to convert these into the active form of vitamin A.
Animal foods contain retinols. Colorful fruits and vegetables contain carotenoids.
Vitamin A can help improve thyroid function:
- It can regulate thyroid hormones and lower TSH
- Helps the pituitary synthesize and regulate TSH
- May lower incidences of immune reactions in autoimmune thyroid diseases
- Prevent cell damage
Recommended Intake of Vitamin A
The Dietary Reference Intakes (DRI) for vitamin A for adult men and women is 900 mcg RAE. Pregnant and breastfeeding women need more at around 770 mg RAE and 1,330 RAE per day.
Since vitamin A is a fat-soluble vitamin it is stored in the body. A high intake of vitamin A supplements may be problematic so it is best to start with food to get more of this nutrient.
Where to Find Vitamin A
Vitamin A can be found in the following foods:
- Carrots
- Spinach
- Sweet potato
- Cantaloupe
- Broccoli and broccoli sprouts
- Mango
- Butternut squash
- Liver
- Apricot
- Pumpkin
- Parsley
- Salmon
- Herring
- Tuna
- Grapefruit
- Egg*
- Turnip greens
- Beef
- Brussels sprouts
- Asparagus
- Romaine lettuce
Thiamin (B1)
Thiamine is one of the nine B complex vitamins. Also known as B1, it is a water-soluble vitamin that needs to be consumed every day. The gastrointestinal tract is where thiamin is absorbed.
Thiamin stays in the liver for only 18 days and is then excreted by the urine. It can also cross the blood-brain barrier.
Its main responsibility is to give cells energy.
Once absorbed into the blood magnesium and an enzyme called thiamin diphosphotransferase converts thiamin into its active form, thiamin pyrophosphate (TPP).
The main function of TPP is to produce energy for the body:
- Producing energy from carbohydrate, fat, and protein metabolism
- Maintain the citric acid cycle
- Maintaining adequate glutamate, aspartate, and gamma-aminobutyric acid (GABA) levels
- Help synthesize nucleic acids, steroids, fatty acids, amino acids, neurotransmitters, and glutathione
- Works as a cofactor to helps transform ribose-5-phosphate back into glycolysis intermediates (ie glucose-6-phosphate)
- Helps release hydrochloric acid needed for digestion
Many people with thyroid conditions have gut dysfunction and low stomach acid. Getting enough thiamin can help to properly digest foods.
Stress can deplete thiamin. Often thyroid patients are also suffering from stress. So monitoring these levels is crucial for your clients.
Low levels of thiamin may result in the following symptoms
- Fatigue
- Loss of appetite
- Irritability, Changes in reflexes
- Tingling or numbness in extremities
- Muscle weakness
- Digestive issues
- Blurry vision
- Changes in heart rate and blood pressure
- Depression
- Pressure on adrenals
- Trouble with carbohydrate metabolism
These are common problems in those with thyroid dysfunction. So getting enough is crucial.
Recommended Intake of Thiamin
Thiamin has a Recommended Dietary Allowance (RDA) of 0.9 mg a day for healthy adult men and women.
The recommended daily intake (RDI) for adults over age eighteen is 1.2 mg/day for men and 1.1 mg/day for women. This is for healthy individuals. Due to absorption issues, those with thyroid conditions may need more than the RDI of this is vitamin.
Where to Find Thiamin (B1)
Thiamin can be found* in whole grains, brown rice, liver, pork, poultry, soybeans, nuts, dried beans, and peas.
The problem is that many of these foods aside from pork, poultry, and liver may not be friendly to the thyroid.
Whole grains, soybeans, nuts, beans, and peas may be problematic for those with leaky gut. Gluten and gluten-free enriched grains should be avoided.
In regards to the other potential food issues, see how your clients feel when they consume them. If it negatively affects them and they are still feeling low energy getting a micronutrient test can tell if a supplement may be needed.
Research says taking 600 mg for one month and reducing it to 200 mg per day improved symptoms of fatigue.
According to research, thiamin supplementation does not pose any toxicities even in excess.
Boron
Boron is an essential trace mineral. It plays a big role in parathyroid gland function.
It also helps with calcium, magnesium, and vitamin D absorption. Some research shows boron may also improve brain health.
It helps with wound healing, immunity, and the regulation of sex hormones. Boron is also anti-inflammatory.
This mineral may have positive effects on the thyroid. One animal study showed boron was able to enhance the secretion of the T3 hormone. Low levels, of boron may also increase thyroid incidences of thyroid abnormalities .
Other research says overexposure to this nutrient may cause goiter. Getting too much can be problematic. It is best to get boron from food sources unless deficient in this nutrient.
Recommended Intake of Boron
There is no recommended intake of boron but the World Health Organization (WHO) estimates an acceptable range for adults is 1 to 13 mg per day.
Where to Find Boron
Apples, prunes, grapes, apricots, dates, and honey all contain boron.
Riboflavin (B2)
Riboflavin is another B vitamin. B vitamins are important for cell growth and development. B2 helps turn food into energy.
Riboflavin deficiencies result from thyroid problems. Signs and symptoms include:
- Skin disorders
- Excess blood edema of the mouth and throat
- Lesions at the corners of the mouth
- Swollen, cracked lips
- Hair loss
- Reproductive problems
- Sore throat
- Itchy and red eyes,
- Poor liver function
- Poor nerve function
Riboflavin deficiencies will impair absorption of other nutrients, especially B vitamins. Severe anemia and cataracts can also develop.
Riboflavin may help improve mood and depression that often accompanies thyroid conditions. This nutrient can also calm inflammation and prevent oxidative stress.
Headaches are common in thyroid dysfunction and riboflavin has been found to lower the incidences of migraines.
Recommended Intake of Riboflavin (B2)
The RDA for riboflavin varies between men and women. Men should get 1.3 mg a day and women need 1.1 mg per day.
Where to Find Riboflavin (B2)
Riboflavin can be found in both animal and plant foods including the following:
- Grass-fed organ meats like kidney and liver
- Pasture-raised eggs
- Green vegetables such as asparagus, broccoli, and spinach
- Fermented dairy*
Riboflavin can be lost when foods are boiled. The best way to maintain the nutrient is by steaming.
B-12
Vitamin B12 is one of the 9 B-complex vitamins. It has several forms and contains the mineral cobalt. The most active forms are Methylcobalamin and 5-deoxyadenosylcobalamin.
This nutrient is needed for energy, red blood cell formation, neurological function, and DNA synthesis.
B12 also helps turn homocysteine into the amino acid methionine.
Methionine helps to form S-adenosylmethionine, a compound needed for the production of DNA, RNA, and hormones.
B12 deficiency occurs in about 40% of those with thyroid conditions. Depletions of this nutrient also can lead to anemia. Anemia is a condition where your body is not producing enough blood cells. It results in fatigue and tired feeling. It is also prevalent in those with thyroid dysfunction.
A deficiency in B12 has also been linked to high levels of homocysteine. Too much homocysteine may cause
The absorption of B12 depends on the presence of hydrochloric acid. Those with thyroid conditions often have low stomach acid and may be at risk for deficiency.
Levels over 450 pg/mL are considered optimal. B12 experts say optimal levels are above 450 pg/mL. Those with symptoms and levels under this number should be treated with supplements.
They also recommend treating patients with normal B12, but elevated urinary methylmalonic acid (MMA), homocysteine, and/or holotranscobalamin (other markers of B12 deficiency).
Recommended Intake of B12
The Recommended Dietary Allowances (RDA) for vitamin B-12 is I.8 micrograms per day.
Where to Find B12
B12 is usually found in animal foods such as
- Grass-fed organic meats (beef, liver)
- Pasture-raised eggs*
- Wild-caught fish
- Organic pasture-raised poultry
Plants do not contain B12. They are often fortified with synthetic B12. This form, cyanocobalamin is poorly absorbed when compared to methylcobalamin and the B12 naturally occurring in foods.
Vitamin C
Vitamin C is sometimes called ascorbic acid. It is a water-soluble vitamin that is good for the thyroid. Its antioxidant properties make it protect cells from external environmental damage.
Free T4, T3, and TSH abnromalities improved with vitamin C. This vitamin may also help reduce antibodies in thyroid autoimmune conditions like Hashimoto’s.
Vitamin C may also affect selenium metabolism. So having too little vitamin C could affect selenium absorption.
Recommended Intake of Vitamin C
The Recommended Dietary Allowances (RDA) for vitamin C varies between men and women. Adult men need to consume 75 mg and women should get 65mg a day [R].
Where to Find Vitamin C
Fruits and vegetables are the best sources of vitamin C. They include
- Citrus fruits (oranges, lemons, grapefruits, pomelos, and limes)
- Kiwi
- Broccoli
- Brussels sprouts
- Cantaloupe
Getting five servings of vegetables can give you more than 200 mg of vitamin C.
As with other nutrients, some foods are fortified with vitamin C. It is best to get it naturally from foods.
Storage and cooking may also alter the content of vitamin C. Steaming may cause vitamin losses and the best way to get vitamin C is to eat foods raw.
Be sure to get vitamin C from vegetables with a moderate intake of low glycemic fruit.
Copper
Copper is an essential trace mineral. It is in all body tissues. It works with iron to help create red blood cells and help increase iron absorption. This mineral also maintains healthy blood vessels, nerves, bones, and immune system.
People with hypothyroidism often have low copper levels. Copper synthesizes tyrosine, a protein that makes up thyroglobulin. Thyroglobulin creates adequate hormone production.
A diet rich in this trace element should help improve thyroid function.
Recommended Intake of Copper
The Recommended Dietary Allowance (RDAs) for copper is 890 micrograms per day.
Where to Find Copper
Copper is in the following foods:
- Nuts*
- Dark leafy greens
- Nutritional yeast (be sure it does NOT contain folic acid)
- Grass-fed organ meats (kidney and liver)
Vitamin D
Every cell needs vitamin D. It improves muscle and nerve function and a healthy immune system. Vitamin D helps the body absorb calcium. This creates strong bones and prevents osteoporosis.
This nutrient also plays a role in preventing inflammation. It also is responsible for cell growth, DNA regulation, and glucose metabolism.
A deficiency in vitamin D can occur in numerous autoimmune diseases including autoimmune thyroid diseases.
Vitamin D can improve leaky gut often seen in thyroid dysfunction. It can help restore the tight junctions in the gut. It also can help improve immune function to fight inflammation.
This nutrient, specifically D3 may help lower TSH levels in those with hypothyroidism.
Types of Vitamin D
Vitamin D has two main forms D2 (ergocalciferol) and D3 (cholecalciferol), that differ chemically only in their side-chain structures. Vitamin D3 is absorbed better than D2. For this reason it form recommended when taking supplements.
Adequate intake of vitamin K2, vitamin A, magnesium, zinc, and boron are also needed for vitamin D metabolism.
Recommended Intake of Vitamin D
The Recommended Dietary Allowance (RDA) of vitamin D for adults is 600 IU. Optimal blood levels of vitamin D are between 60 and 90 ng/mL.
All patients with thyroid disorders should have their vitamin D levels checked. This is especially true for Graves disease and other forms of hyperthyroidism. Symptoms of hypothyroidism and hyperthyroidism can mimic nutritional deficiencies like vitamin D.
Where to Find Vitamin D
Vitamin D rich foods include:
- Fish with bones
- Fatty fish (salmon, tuna, herring, trout, mackerel)
- Mushrooms exposed to ultraviolet light
Beef, liver, and egg yolks also contain some vitamin D.
Many food products are also fortified with vitamin D but they often contain synthetic D2 and are not absorbed as well as vitamins that occur naturally in foods.
Consuming fat with vitamin D foods will enhance absorption.
Vitamin D can also be obtained from the sun and blue light therapy lamps. Getting 10 to 15 minutes of sunlight around 12 pm is the best time to get vitamin D.
Those with a history of skin cancer should consult with a healthcare professional before getting any sunlight exposure.
When To Supplement Vitamin D
For those who do not eat foods with vitamin D or get enough sunlight you may want to supplement liquid (cholecalciferol) D3 drops* to maintain vitamin D levels.
If your clients have vitamin D levels lower than 60 ng/mL they may benefit from taking a supplement*.
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Vitamin E
Vitamin E is the collective name for a group of fat-soluble compounds with distinctive antioxidant activities. There are about eight forms of vitamin E but the ones found needed by humans are alpha-tocopherol.
It stops the production of reactive oxygen species (ROS) better known as free radicals. Thyroid conditions have increased oxidative stress. Vitamin E may have beneficial effects on thyroid cells.
Vitamin E and selenium may partially restore 5′-monodeiodinase. This is an enzyme responsible for producing the thyroid hormone T3.
The combination of vitamin E and thyroid medication, levothyroxine reduced oxidative stress and improved thyroid function in animals.
Antioxidants like vitamin E may protect the thyroid from medication-induced hypothyroidism. Animals given vitamin E with methimazole had smaller thyroids along with less suppression of T4 and T3 hormone levels.
Vitamin E may also improve damage from excessive iodine intake.
Vitamin E deficiency has a negative impact on the physical structure of the thyroid and pituitary gland responsible for producing thyroid-stimulating hormone (TSH).
Recommended Intake of Vitamin E
Vitamin E (Alpha-Tocopherol)’s Recommended Dietary Allowances (RDA) for adults is 15 mg per day.
Experts say those with conditions like Hashimoto’s have high oxidative stress and need intakes of around 268 mg.
Where to Find Vitamin E
Vitamin E is naturally found in nuts, seeds, and leafy green veggies. The following foods are rich in this nutrient:
- Sunflower seeds*
- Hazelnuts*
- Avocado
- Swiss chard
- Olive oil
- Spinach
Soybean*, peanut, sunflower, sesame, canola, corn, and other vegetable oils do have vitamin E but these tend to be very processed and high in omega 6 fats. They may increase the already existing oxidative stress present in thyroid conditions.
Vitamin E may also be added to foods, it is best to stick with foods that naturally contain this vitamin.
Folate NOT Folic Acid
Folate and folic acid are often used interchangeably to describe the water-soluble B9 vitamin. However, they are two very different substances.
Folate is the naturally occurring form of B9 in foods. Folic acid is the synthetic version added to foods and supplements.
When folic acid is digested it is should be converted into the active form, methyl folate or 5-methyl-THF. However, many people with thyroid conditions can have issues with this due to gut dysfunction and a genetic mutation called MTHFR.
MTHFR is a genetic condition where the body cannot break folic acid down into its active form. That is why it is recommended to avoid foods with enriched grains and supplements with folic acid.
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Folate acts as a coenzyme and helps to produce DNA, RNA, and amino acids. It is also responsible for proper cell division. Low levels may result in megaloblastic anemia.
Just like B12, folate can convert homocysteine into methionine. Methionine is needed to make DNA.
Subclinical hypothyroidism has been associated with cardiovascular risks including hypertension, elevated cholesterol, and atherosclerosis due to elevated homocysteine levels. Elevated homocysteine occurs due to a defect in enzyme activity. This prevents the proper conversion of homocysteine to methionine.
Folate deficiencies have also been associated with high homocysteine and hypothyroidism. Folate deficiency also increases the risk of hyperthyroidism and Graves’ disease.
Recommended Intake of Folate
The Recommended Dietary Allowances (RDA) of folate is 400 micrograms of dietary folate equivalents (DFEs).
Where to Find Folate
It is important to get folate from real foods and not synthetic forms of folic acid added to foods during processing. Good food sources of folate include:
- Leafy green vegetables (spinach, collard greens, romaine, etc)
- Asparagus
- Papaya
- Beans*
- Lentils*
- Avocados
- Brussels sprouts
- Nuts*
- Seeds*
- Beets
Getting enough folate from food sources is particularly important for those with the MTHFR gene variation.
For clients with gut issues eating veggies may be hard on digestion. Making smoothies and pureeing veggies can ease the stomach.
If your client is having a deficiency supplementation may be needed. Be sure to get methyl folate that is in the active form so it is easily absorbed.
Fiber
Fiber is a nutrient found in plant foods that the body is unable to digest. It comes in three forms:
- Soluble
- Insoluble
- Fermentable
Soluble fiber is dissolved in water and forms a gel-like substance in the digestive tract. This is what slows digestion and keeps you full. Insoluble fiber helps to add bulk to the stool and helps it move through the digestive tract. This fiber prevents constipation.
Fermentable fiber is both soluble and insoluble fibers that produce healthy bacteria when digested in the gut.
Fiber is helpful to those with thyroid issues. It is a great nutrient for improving cardiovascular and digestive health as well as stabilizing blood sugar.
Recommended Intake of Fiber
Recommendations of fiber are 25 to 35 grams a day.
Where to Find Fiber
Fiber is found* in whole grains, vegetables, fruits, beans, and legumes. Some of these foods can be problematic for those with thyroid conditions. Gluten can be proinflammatory for the thyroid. Also, some individuals have issues digesting beans and legumes.
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Those with thyroid conditions may have gut dysfunction. This means that too much fiber too fast may cause digestive distress. That is why this nutrient should be consumed in smaller quantities.
Some indigestible fibers have even caused bowel obstructions in those with thyroid conditions. So taking caution with adding fiber might be a good idea.
Adding a digestive enzyme can also help to ease the stomach pain from high fiber foods.
Iodine
Iodine is an essential nutrient. As a component of thyroxine (T4) and triiodothyronine (T3), it is responsible for thyroid hormone production.
Thyroid hormones are needed for many biochemical reactions including protein synthesis and enzyme function. They also regulate metabolic activity. Adequate production will ensure adequate growth, development, and metabolism. They also help with bone formation.
Both TOO much and TOO little iodine can be harmful to the thyroid.
Too little can impair thyroid function and lead to the following:
- Goiter
- HYPOthyroidism
- Increase risk of thyroid cancer
Too much iodine can also be a problem. Excess iodine will have similar effects:
- Stop thyroid hormone production
- Increase TSH
- HYPERthyroidism
- Increased risk of thyroid cancer
Iodine is often given as a treatment for iodine deficiency. It is also a treatment for thyroid cancer. Hyperthyroidism can occur if someone is given too much iodine. Excess iodine intake can lead to inflammation of the thyroid (thyroiditis) and canceR.
Hydrogen peroxide is produced as a byproduct of thyroid hormone production. This free radical can be toxic to the body. An excess in iodine can increase hydrogen peroxide production. When there are not enough antioxidants like selenium and glutathione available inflammation and autoimmunity can ensue.
Recommended Intake of Iodine
Research shows the thyroid gland needs between 50 – 250 micrograms (mcg) per day. Those with thyroid conditions may need only around 52 mcg of iodine per day.
The World Health Organization (WHO) shows various iodine intakes can cause the following thyroid issues:
Less than 20 mcg: Endemic (native) goiter, congenital hypothyroidism
20-49 mcg: Pediatric goiter, low rate of adult disease
50-99 mcg: Lowest disease rate and reversal of autoimmune thyroid disease
100-199 mcg: Low thyroid disease rate
200-299 mcg: Iodine-induced hyperthyroidism, autoimmune thyroid disease, goiter, hypothyroidism
More than 300 mcg: Hypothyroidism, goiter, autoimmune thyroid disease
As you can see even with just 200 mcg thyroid complications can occur. Those with thyroid conditions may need to restrict their intake to even lower.
According to iodine expert, Dr. Christianson, the optimal amount of iodine to reverse thyroid disease is 50 to 99 mcg per day. Using this level may help people lower thyroid medication levels and possibly wean off (under the care of a medical professional of course).
Restricting iodine to less than 100 mcg a day for one to three months may also help lower antibody production and improve Hashimoto’s.
A survey of 356 people with Hashimoto’s found that most people felt worse when taking a high dose of iodine. Iodine restriction also made 31.7 of people feel better. Seven percent felt worse with iodine restriction.
This tells you that iodine levels need to be individualized depending on the person’s thyroid markers.
Where to Find Iodine
Iodine is found not only in foods but also can be lurking in personal care products, medications, and supplements. So care should be taken to find out how much iodine is being consumed daily.
Food Sources of Iodine
Food sources include the following:
- Seaweed*
- Kelp*
- Spirulina*
- Chlorella *
- White cod and other fish
- Shellfish
- Yogurt and other dairy products*
- Eggs*
- Pole line caught tuna fish
- Green peas*
- Bananas
- Vegetables grown in iodine-rich soils
- Commercial baked goods
- Cured, packaged, processed, and canned foods and meats
- Foods containing red food dyes
- Carrageenan
- Chocolates
- Soybeans and soy-based products*
- Legumes including red kidney beans, lima beans, navy and pinto beans*
- Skins of root vegetables (especially potatoes)
Non-Food Sources of Iodine
Non-food sources of iodine include:
- Iodized table salt
- Skincare products (makeup, lotions, creams, moisturizer
- Shampoos and conditioner
- Sunscreens
- Thyroid support blend supplements and vitamins
- Medications
When deciphering iodine in a label it can be listed as:
- Ammonium iodide
- Potassium iodide
- Sodium iodide
- Iodoform
- PVP-iodine
- Hydroxypropyl bistrimonium diiodide
- TEA-hydroiodide, ethiodized oil
- Iodopropynyl butylcarbamate
- Fucus vesiculosus extract (seaweed extract)
- Laminaria digitata extract (kelp extract)
Iodine is found in the following medications:
- Amiodarone
- Benziodarone
- Calcium iodide
- Diiodohydroxyquin (Yodoxin)
- R-Gen
- Echothiophate iodide ophthalmic solution (phosphine)
- Hydriodic acid syrup
- IIodochlorhydroxyquin (Entro-Vioform)
- Iodinated glycerol (Iophen)
- Idoxuridine ophthalmic solution (Herplex)
- Isopropamide iodide (Darbid)
- Potassium iodide (KI)
- Mudrane
- Lugol’s Solution
- Niacinamide hydroiodide
- Ponaris nasal emollient
- Supersaturated potassium iodide (SSKI)
- Injectable solutions: sodium iodide
- Topical antiseptics: diiodohydroxyquin cream (Vytone), iodine tincture iodochlorhydroxyquin cream (Vioform), Cellasene, iodoform gauze (NuGauze), povidone-iodine (Betadine)
- Radiology contrast agents: diatrizoate meglumine sodium (Renografin), iodized oil, iopanoic acid (Telepaque), ipodate (Oragrafin), iothalamate (Angio-Conray), metrizamide (Omnipaque), ethiodized oil (Lipiodol)
As with all nutrition, iodine intake needs should be individualized based on thyroid levels and how someone reacts to intake. It is best to stick to lower levels based on the WHO guidelines and see how it affects them.
Iron
This mineral is integral to growth and development. It is used to make hemoglobin a protein in red blood cells. Iron helps move oxygen from the lungs into various body cells. Iron is also needed to make the protein myoglobin which brings oxygen to the muscles.
Not getting enough of this nutrient can lead to deficiency and anemia. Deficiency signs include fatigue, digestive issues, poor memory (brain fog) and concentration as well as low immunity.
Iron is integral to the thyroid because it helps convert T4 into the active thyroid hormone T3. An iron deficiency may lead to hypothyroidism.
Iron is also needed to make iodine found in thyroid cells. Iron is also used to produce thyroid hormones along with storage from T4 to active T3.
Caffeine has been found to impair iron and zinc absorption which are critical nutrients needed for optimal thyroid function.
The polyphenols in coffee can also bind to nonheme iron and prevent intestinal absorption.
Even combining nonheme iron with just 150 to 250 ml of coffee has been found to reduce iron absorption by 24 to 73 percent. Consumption of coffee should also be avoided with iron intake.
Ferritin (Iron Storage) Levels Should Be Considered
Low ferritin without anemia will result in fatigue, difficulty breathing, and hair loss. Many are deficient or low in ferritin, the body’s iron protein stores.
Menstruating and postpartum women are particularly at risk for low iron and ferritin levels. Gut dysfunction such as H. pylori, low stomach acid, heavy metal toxicities, and those with a vegetarian or vegan diet are more likely to have low iron levels.
Ferritin can still be low even if iron levels come out as normal. So getting tested for ferritin is important in those with thyroid conditions.
Normal ferritin levels for women are between 12 and 150 ng/mL.
Optimal ferritin levels are between 90-110 ng/mL
Recommended Intake of Iron
The Recommended Dietary Allowances (RDA) for iron varies depending on the age and sex of a person. It is as follows:
- 14-18-year-old men: 11 mg
- 14-18-year-old women: 15 mg
- 19-50-year-old men: 8 mg
- 19-50-year-old women: 18 mg
- 51+ men and women: 8 mg
Iron intake may need to be higher for those with thyroid issues. Supplementation may also be needed depending on ferritin and iron levels.
If there is low stomach acid this may prevent absorption and decrease iron and ferritin levels. Addressing gut dysfunction will help to improve how much iron is utilized.
Be sure to periodically check iron levels to make sure build-up does not occur.
Where to Find Iron
Iron comes in two forms: heme iron and nonheme iron
Heme iron comes from hemoglobin and myoglobin in animal food sources. It represents 10-15% of the total dietary iron intake of meat-eaters.
Heme iron consists of animal sources including low mercury wild seafood, grass-fed organ meats, and free-range poultry.
This iron is much better absorbed than nonheme iron and contributes up to 40% of total absorbed iron.
Nonheme iron consists of plant* sources. This includes the following:
- Nuts*
- White beans
- Pumpkin seeds*
- Lentils*
- Spinach
- Peas
Plant sources of iron are better absorbed when eaten with foods that contain vitamin C like citrus fruits, tomatoes, and broccoli.
Meat, seafood, and poultry contain both heme and nonheme iron. Some foods are fortified with iron but these synthetic vitamins may not be absorbed as well as from naturally occurring food sources.
Vitamin K
Vitamin K is a fat-soluble vitamin referring to the quinone structures. It is important for bone health. This vitamin helps absorb vitamin D. It also plays a role in thyroid function.
Low vitamin K slowed blood clotting in animals. Another study showed thyroid hormone levels affected blood clotting factors.
Some drugs interact with vitamin K.
This vitamin is made up of three types:
- K1
- K2
- K3
Vitamin K1 The Plant Derived Phylloquinone
Vitamin K1 is a plant-derived phylloquinone. K1 is known for its blood clotting effects.
Having low thyroid hormone (HYPOTHYROIDISM) and a vitamin K deficiency increases the risk of bleeding.
Those with a vitamin K deficiency and elevated levels of thyroid hormone (HYPERTHYROIDISM) are at risk of thrombosis or blood clots within a blood vessel.
The Recommended Intake of K1 Phylloquinone
The Adequate Intakes (AI) for Vitamin K1 is 75 mcg a day.
Where to FInd K1 Phylloquinone
K1 rich foods include dark leafy greens like kale and spinach, beet greens, collards, broccoli, and Brussels sprouts.
Those on blood-thinning medications should talk to their doctor about their K1 intake.
Vitamin K2: Menaquinones (MK-4 and MK-7)
The menaquinones make up vitamin K2. MK-4 and MK-7 are typical versions. They denote the length of the molecular structure side chain.
- Menaquinone-4 (MK-4) is synthesized in animals
- Menaquinone-7 (MK-7) is made by bacteria
K2 has minimal effect in clotting, it is effective in brain function.
MK-4 can help lower the risk of cardiovascular disease.
MK-4 can also be produced by the body when there is the presence of healthy gut bacteria.
Antibiotics can decrease the amount of K2 in your gut. It is also essential for Vitamin D and calcium absorption.
Recommended Intake of K2 Menaquinones (MK-4 and MK-7)
There are no specific recommendations for K2 but it is an important nutrient needed for bone health. Looking at undercarboxylated osteocalcin can indicate K2 status and if supplementation is necessary.
Adequate vitamin D absorption requires vitamin K2. So low vitamin D may mean possible low K2 as well.
Please note that some K2 supplements do contain fermented soy and those with sensitivities to this may want to avoid these supplements.
Those on blood thinners may need to speak with their doctor before taking any K2 supplements.
Where to FInd K2: Menaquinones (MK-4 and MK-7)
K2 menaquinones MK-4 and MK-7 are in:
- Pasture-raised eggs*
- Grass-fed dairy
- Grass fed-beef
- Grass-fed liver
- Chicken
- Fermented foods*
- Natto*
Other fermented foods contain K2 but the levels vary depending on the types and quantity of bacteria present.
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LEARN THE BENEFITS FOR NATTO FOR THYROID NUTRITION
Vitamin K3: Menadione
Vitamin K3 is known as menadione. It is a synthetic form of vitamin K. K3 was shown to damage liver cells and is no longer used in dietary supplements or fortified foods. It is currently still being used in animal feed because it can convert it to the active form of vitamin K.
Though harmful to humans, as an animal feed it shows no problems.
Protein
This nutrient makes body cells, tissues, and organs. It can help with the healing process, weight loss, and satiety. Those with thyroid dysfunction also need to make sure they are getting enough protein at each meal.
Getting adequate protein can help to improve blood sugar imbalances which are often a problem in thyroid conditions.
Those with thyroid conditions often have gut issues. This makes digesting protein difficult. Taking digestive enzymes can help but another way to get the protein that is easy on the stomach is by making smoothies.
Those with thyroid conditions can benefit from a smoothie with a high-quality protein powder. Gluten, dairy, soy, and egg may be culprits and should be avoided in some people.
For those with sensitivities you can opt for the following protein powders instead:
- Pea protein
- Hemp protein
- Organic Grass-fed Hydrolyzed beef protein (bone broth powder)
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Recommended Intake of Protein
The recommendations for protein vary from person to person. Typical protein intakes run between 0.36 and 0.45 grams of protein per pound of body weight. So if you weigh 100 lbs you should get 36 to 45 grams of protein a day.
Those who are more active need more protein and should get as much as 0.91 grams of protein per pound of body weight. So that 100 lb person would need 91 grams of protein.
Older adults and those with chronic diseases should be getting more protein. Usually about 45 to 59 grams of protein per pound of body weight.
Those with severe kidney issues not on dialysis should limit protein intake since their kidneys may not be able to filter the protein properly.
Where to Find Protein
The quality of the protein is important as well as the quantity. If you are eating animal-based proteins you want to make sure you are eating organic non-GMO grass-fed beef and lamb, antibiotic-free-range chicken and turkey, pasture-raised organic eggs, and/or use a grass-fed beef protein powder.
Plant-based proteins include* raw nuts and seeds, chia seeds, flaxseeds, legumes, beans, gluten-free grains like quinoa, and plant-based protein powder like hemp powder.
Protein intakes will vary by client. It is best to use an individualized approach.
Magnesium
Magnesium is an important nutrient needed for many processes including:
- Muscle muscle
- Nerve function
- Blood sugar balance
- Blood pressure balance
- Protein synthesis
- Bone formation
- Making DNA
This nutrient is integral to staying healthy especially when your thyroid is not functioning properly. Benefits of getting adequate magnesium include the following.
Those with thyroid often have trouble sleeping; this can be due to low magnesium levels.
Taking 500 mg of magnesium daily improved sleep in older adults when compared with a placebo.
Thyroid conditions can also result in headaches and migraines. Those with headaches often have lower levels of magnesium.
Three months of a daily dose of 600 mg of magnesium (trimagnesium dicitrate) reduced the number of migraine attacks.
Magnesium deficiency may also result in menstrual cramps, anxiety, and joint pain.
The thyroid is responsible for regulating glucose and blood pressure. When magnesium levels are low hypertension and risk of diabetes are increased. Magnesium can help regulate and lower both sugar and blood pressure.
Too much or too little thyroid hormones can affect bone formation. So having thyroid conditions may lead to osteoporosis and demineralized bones. Lower magnesium levels were found in women with osteoporosis. Magnesium can help regulate bone homeostasis. Bone mineral density is improved with this mineral.
Magnesium also helps with vitamin D metabolism and absorption. Boron can also improve magnesium metabolism and increase serum levels.
Recommended Intake of Magnesium
The Recommended Dietary Allowance (RDA) for Magnesium varies for different ages and sexes. They are as follows:
- Men 19-30 years old: 400 mg
- Women 19-30 years old: 310 mg
- Men 31 years and older: 420 mg
- Women 31 years and older: 320 mg
- Pregnant women
- 14-18 years old: 400 mg
- 19-30 years old: 350 mg
- 31-50 years old: 360 mg
- Breastfeeding women
- 14-18 years old: 360 mg
- 19-30 years old: 310 mg
- 31-50 years old: 320 mg
Where to Find Magnesium
Magnesium is found in both plant and animal foods. Good sources include leafy green vegetables, legumes, nuts, seeds, and gluten-free whole grains. Most foods that contain fiber will provide magnesium. The richest sources of magnesium include the following foods:
- Pumpkin seeds
- Chia seeds*
- Almonds*
- Spinach
- Brazil nuts*
- Cashews*
- Black beans*
- Brown rice
- Baked sweet potato
- Edamame*
- Yogurt, kefir, and fermented dairy*
- Chocolate or unprocessed cacao
Tap, mineral, and bottled water may also contain magnesium but the levels vary.
Manganese
Manganese is an essential trace mineral that works as a cofactor for many enzymes. It is needed for amino acid, cholesterol, glucose, and carbohydrate metabolism. This nutrient works as an antioxidant to scavenge reactive oxygen species (ROS). It is also needed for
- Bone formation
- Reproduction
- Immune function
- Blood clotting
- Blood sugar regulation
- Wound healing
- Reduce PMS symptoms
Decreases in iron status can increase manganese absorption. This means an iron deficiency may lead to toxicity in manganese. As to why this happens is unknown. One possible thought is that iron and manganese share the same transporter in the intestine.
Recommended Intake of Manganese
The Recommended Dietary Allowance (RDA) of manganese differs among men and women
- Adult men: 2.3 mg
- Adult women: 1.8 mg
- Pregnant women 2.0 mg
- Breastfeeding women 2.6 mg
Humans absorb only about 1% to 5% of dietary manganese. Men may absorb manganese less efficiently than women. This could be because they have a higher iron status.
Where to Find Manganese
Manganese foods sources include the following:
- Gluten-free whole grains
- Clams
- Oysters
- Mussels
- Nuts
- Legumes
- Leafy vegetables
- Coffee
- Tea
- Spices
- Drinking water
Selenium
Selenium is a trace element that is essential for proper thyroid hormone production. It is also responsible for
- Reproduction
- DNA production
- Immunity
- Preventing free radical production
This nutrient exists in two forms: inorganic and organic.
The inorganic version consists of selenate and selenite. The organic version consists of selenomethionine and selenocysteine. Both are good dietary sources of selenium.
The selenium content of food varies depending on how much is in the soil. In human tissues, most selenium is in the form of selenomethionine. Selenium is needed to make the amino acid methionine.
Most selenium is in skeletal muscle. It makes up 28 to 46% of the total amount in the body. When measuring levels the blood and urine are best for knowing recent intake. Nail or hair samples are used to analyze long-term selenium intake.
Selenium helps to neutralize hydrogen peroxide. This free radical is a metabolite of thyroid hormone production. It can help heal inflammation from excess iodine.
Selenium can also lower thyroid antibodies when paired with medications in autoimmune thyroid conditions like Hashimoto’s.
The antioxidant effects of selenium can protect thyroid cells from free radical production by ROS. Oxidative stress from free radical production can destroy cells and cause more thyroid damage.
A selenium deficiency can prevent T4 from converting into the active T3 thyroid hormone.
Recommended Intake of Selenium
The Recommended Dietary Allowance (RDA) for selenium is 55 micrograms (mcg) for healthy individuals.
Depending on a person’s current selenium and iodine levels this may be too low for some people who are experiencing thyroid conditions. Experts say to get the full benefit of selenium a dose of 200 to 400 mcg should be taken. The upper limit is also 400 mcg.
Where to Find Selenium
Selenium is available in many foods. A rich source of selenium includes:
- Seafood
- Grass fed-organ meats (liver, kidney)
- Pasture-raised organic eggs*
- Free-range poultry
- Wild low mercury fish
- Kefir and other grass-fed dairy products*
- Brazil nuts*
Plant foods also contain selenium but the amount depends on how much selenium is in the soil and taken up by the plant. Brazil nuts are a good source of selenium depending on the soil. Just one ounce (¼ cup) of Brazil nuts can have up to 544 mcg of selenium.
Zinc
Body cells contain the mineral zinc. It works as an enzyme facilitating about 100 chemical reactions in the body. It helps with the following:
- Cellular metabolism
- Immune function
- Protein synthesis
- Wound healing
- DNA production
- Cell division
- Helps taste and smell function
- Growth and development during pregnancy, childhood, and adolescence
Since there is no storage system for zinc it needs to be maintained daily.
Optimal thyroid function relies on adequate levels of zinc. It helps to produce and regulate various thyroid hormones:
- Thyrotropin-releasing hormone (TRH)
- Thyroid-stimulating hormone (TSH)
- Triiodothyronine (T3)
- Thyroxine (T4)
So elevated TSH levels may also indicate a deficiency of zinc.
The thyroid also needs this nutrient for its healing and immunity properties. Getting enough zinc may improve and prevent inflammation and allergies in autoimmune conditions.
Gut dysfunction is common in thyroid problems. Zinc may improve gut health. It can heal tight junctions and seal a leaky gut. A deficiency will have the opposite effect and increase gut permeability.
Alcohol consumption also decreases the intestinal absorption of zinc. Zinc is also depleted in urine. For those who drink alcohol, zinc levels should be monitored.
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Zinc may also prevent weight gain when following a nutrient-rich diet.
A deficiency can result in poor wound healing, weakened immune function, reduced taste and smell, and thick brittle, peeling, or white-spotted nails. When the liver enzyme alkaline phosphatase (ALP) dips below 70 IU/L it can also be a sign of zinc and/or magnesium deficiency.
Those with Irritable Bowel Syndrome (IBS) and Celiac disease are at risk for a deficiency because they absorb less zinc than a healthy individual.
Zinc is a nutrient that is essential for vitamin D absorption.
Recommended Intake of Zinc
The Recommended Dietary Allowance (RDA) for zinc vary for men and women:
- Adult Men: 11 mg
- Adult Women: 9 mg
Where to Find Zinc
Zinc is in a variety of foods. Good sources include the following:
- Grass-fed beef
- Chicken
- Oysters
- Crab
- Lobster
- Porkchop
- Beans*
- Pumpkin seeds*
- Yogurt*
- Cashews*
- Chickpeas*
- Swiss cheese*
- Gluten-free oatmeal*
The zinc found in beans and grains is not absorbed well. This is because they contain phytates. Grains, cereals, nuts, and seeds contain these compounds.
These compounds may increase the potential for zinc deficiency. For vegetarians and vegans on a plant-based diet, this needs to be addressed. They should get a 50 percent higher zinc intake due to the decreased absorption of phytates.
Caffeine is another phytate-containing food that can impair zinc absorption. Coffee can also reduce zinc bioavailability by 21 to 32 percent in vitro studies. This may affect humans the same way. Monitoring the effect of caffeine on thyroid function is important.
How To Evaluate Micronutrient Status
If you want to evaluate your client’s diet a great tool to use is Cronometer*. This is one of the few food tracking apps that tracks micronutrients. This is a great starting place to see how many of the essential nutrients someone is getting in their diet on a daily basis.
Even with diet, there can be some gaps in nutrition due to
- Environmental factors
- Poor gut health related to thyroid and other health conditions
- Medications
- Stress
Additionally, if someone has very low levels of a particular nutrient they may need to supplement. This can be found by doing a micronutrient test.
As a nutrition practitioner, you can sign up with Vibrant or order micronutrient tests from Ultalabs*.
Final Thoughts On Nutrients for Thyroid
As you can see there are many essential nutrients for thyroid function. Without many of these, there can be an inadequate production of thyroid hormones. Looking at the diet is a good way to improve the status of these nutrients.
However, it may also be beneficial to get a micronutrient test* to discover any possible depletions. If you find any deficiencies be sure to optimize their nutrition with supplements when needed. Be sure to retest for nutrient depletions and thyroid hormone function. This helps to see how effective treatment is working.
*Some of these links are affiliate links, which means when you sign up or purchase from these links we may receive a small commission at no extra cost to you. Learn more in our disclosure statement.
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