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Thyroid hormone replacement medications like levothyroxine are the best way to increase your thyroid function. But even when your thyroid levels are “normal”, you may still experience symptoms of hypothyroidism, also known as an underactive thyroid, including

• Brain fog
• Fatigue
• Muscle and joint aches
• Weakness

So why does this happen? One reason could be a deficiency in vitamins essential for maintaining a healthy thyroid. Thiamine is one of these vitamins. Even a mild thiamine deficiency can make you experience these symptoms. Ahead, we will learn about thiamine, its role in your body, and its connection to medical conditions such as hypothyroidism and its impact on your thyroid.

THYROID GUIDE

Your Guide To Thyroid Medication

Optimizing your thyroid levels with thyroid hormone replacement medication is usually the first step in minimizing symptoms.

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Thiamine, also known as vitamin B1, plays a key role in turning the food you eat into energy for your cells. Because of this, your body needs appropriate levels of thiamine for growth and development and to help your cells function. Without it, your cells don’t get the energy they need to function, causing:

• Confusion
• Fatigue
• Heart problems
• Loss of appetite
• Muscle aches and weakness
• Short-term memory loss
• Weight loss

Sound familiar? Except for weight loss, these symptoms are like those seen in hypothyroid patients. Hypothyroidism causes weight gain, not loss. Those with beriberi, a severe thiamine deficiency, may also have:

• Decreased muscle mass
• Numbness or tingling in feet and hands
• Poor reflexes

Thiamine is a water-soluble vitamin, meaning that extra amounts are not stored in your body, but rather removed through your urine. Thus, you need a steady amount of thiamine to meet your body’s needs through your diet or thiamine supplementation.

Dietary sources

Many foods are naturally rich in thiamine. But some foods have thiamine added to them. The following are great sources of thiamine:

• Beans
• Fish
• Fortified or enriched white rice, cereal, and pasta
• Pork
• Whole grains like brown rice, quinoa, and whole wheat bread

But, coffee and tea prevent your body from absorbing thiamine by breaking it down before your body can absorb it. Drinking large quantities of these beverages may affect your thiamine levels.

Autoimmune protocol diet

Those with thyroid conditions such as Hashimoto’s thyroiditis, an autoimmune disorder of your thyroid, sometimes follow the autoimmune protocol diet (API). This diet limits foods that can trigger an inflammatory reaction by emphasizing eating nutrient-rich foods like

• Fruits
• Minimally processed foods
• Vegetables.

Since fruits and vegetables are not the optimal sources or diet for thiamine, those that follow a strict API diet may be at risk for developing a thiamine deficiency.

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Thiamine supplements

Ideally, you would get enough thiamine from food sources. But when you can’t, thiamine supplements are a great way to increase your thiamine levels.

Benfotiamine, a type of thiamine made in a lab, has been shown to block specific food compounds called advanced glycation end products. These products cause inflammation and put oxidative stress on your body. By blocking these food compounds, those with Hashimoto’s may see improvement in their symptoms.

Since extra thiamine leaves your body, taking a thiamine supplement is relatively safe. Yet, always be sure to talk to your healthcare provider before starting any supplements.

Choosing a supplement can be hard. Try picking a high-quality one from a reputable brand. Ask your pharmacist or thyroid provider for recommendations.

In general, healthy males older than 19 years of age need 1.2 mg of thiamine per day, while healthy females in the same age range need 1.1 mg per day. Daily thiamine requirements increase during periods of

• Breastfeeding
• Excessive exercise
• Pregnancy
• Sickness
• Stress
• Trauma

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While most people living in the United States meet their recommended daily allowance for thiamine, factors that can influence your thiamine levels include:

• Lack of absorption from your gut
• Medications like furosemide (Lasix) or antacids
• Poor dietary intake, possibly due to restrictive dieting or chronic alcohol abuse

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Your gut microbiome consists of good bacteria and viruses that help absorb nutrients from your food. Any changes in digestive enzymes, gut movement, and the acidity in your GI tract can affect the microbiome.

Those with hypothyroidism have lower amounts of stomach acid. Thus changing the acidity of your GI tract and potentially decreasing thiamine absorption. Without enough thiamine in your GI tract, bad bacteria have a chance to grow, further changing the microbiome.

Normally, the lining of your GI tract forms a barrier preventing bad toxins and bacteria from entering your body. But, as your microbiome changes, they may leak into your body, causing what is known as a leaky gut.

This leaking of bad toxins and bacteria may trigger the start of an autoimmune disorder like Hashimoto’s. A 2018 study showed that those with Hashimoto’s have an alteration in their gut microbiome. In summary, changes in your microbiome not only affect thiamine absorption but can also trigger autoimmune disorders.

A 2014 study showed a link between thiamine deficiency and hypothyroidism-associated fatigue. But, the study only had 3 participants! Therefore, more studies are needed to confirm the results. The study showed:

The three participants were taking thyroid hormone replacement medication and had normal thyroid levels. But they were still experiencing fatigue. Participants had thiamine levels measured before and after starting on daily oral thiamine or parenteral thiamine, every four days. Results showed partial or full improvement in their fatigue within hours to days.

Besides improving fatigue, other potential benefits of taking thiamine include improving leaky gut, cognitive function, and heart health.

The best way to determine your thiamine levels is through two different types of blood tests:

• Thiamine diphosphate (ThDP), the active metabolite of thiamine, helps determine how much thiamine you have in your body.
• Erythrocyte transketolase (ETK) activity levels show how well thiamine functions in your red blood cells. Your red blood cells transport thiamine around your body.

These levels are used to determine a ratio that helps determine if you are thiamine deficient or not.

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Thiamine plays an important role in our thyroid health. Knowing your thiamine level is the first step to addressing a deficiency. You can work with one of our thyroid specialists to help you understand what your thiamine levels mean and determine the next best steps to take for your thyroid health.

If a deficiency is noted, working with our on-staff team of thyroid dieticians can help you navigate a supplement protocol, and foods, and support you if you are also implementing an AIP-based diet to help find and alleviate food triggers and sensitivities.

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