Addressing the Underlying Cause of Brain Fog
To get to the root cause of brain fog in chronic disease, we must start with the basics. Optimizing thyroid hormones should be the first item to check off in addressing brain fog for most people. Next, since so many of the causes of brain fog are based in poor gut health, we must eliminate food intolerance that may lead to intestinal permeability (leaky gut), support proper digestion of the food we eat, and address nutrient deficiencies that may be contributing to symptoms of brain fog.
Checklist of What Needs to be Looked at
1. Optimize TSH Levels
TSH (Thyroid Stimulating Hormone) is a pituitary hormone that responds to low/high amounts of circulating thyroid hormone. While the standard reference range for TSH is 0.2-8.0 μIU/mL, a new normal reference range was defined by the American College of Clinical Endocrinologists to be between 0.3-3.0 μIU/mL. Functional medicine practitioners have defined that normal reference ranges should be between 1 and 2 μIU/mL, for a healthy person not taking thyroid medications. Anecdotally, most patients feel best with a TSH between 0.5-2.0 μIU/mL. Get your TSH checked with UltaLab Tests or your primary care provider.
If your TSH test shows a TSH level above 2.0 μIU/mL, even when all other thyroid tests fall within normal ranges, this is considered subclinical hypothyroidism. This means your thyroid is losing its ability to make enough thyroid hormone. At this point, you may benefit from starting on a thyroid medication (or increasing your current dose). For many, getting your TSH levels within optimal ranges will relieve many of the common hypothyroid symptoms, including brain fog.

2. Optimize T3
Some people may not properly convert T4 to T3 (the active thyroid hormone). (There are many factors that may contribute to a person not being able to properly convert thyroid hormone, including liver congestion, stress, low zinc levels, and other nutrient deficiencies… which are all common in those with chronic disease!) This is why many people continue to struggle with thyroid symptoms such as hair loss, brain fog, weight gain, depression and fatigue, even after they’ve started taking thyroid medication.
Studies have suggested that T4-only therapy might not be enough to address the symptoms of hypothyroid patients, especially those related to mental well-being, such as brain fog and depression; and people who continue to have thyroid symptoms despite having normal TSH levels may benefit from a trial of T3, in addition to T4 medication. Get your T3 checked with UltaLab Tests or your primary care provider.
If this sounds like something you may benefit from, you do have a few options when it comes to T3-containing medications:

• T3 medications: These contain liothyronine and include the brand names Cytomel, Armour Thyroid, and Nature-Throid. They offer the active, short-acting, T3 thyroid hormone.

• NDT: One T4/T3 medication option is Natural Desiccated Thyroid (NDT, sometimes called desiccated thyroid extract, or DTE) hormones. These medications are derived from the thyroid glands of pigs and are considered bio-identical to the hormones produced by our thyroid glands. Many patients who did not feel well on conventional treatments have reported feeling much better after switching to a NDT medication like Armour Thyroid, Nature-Throid or WP Thyroid.
• Compounded medications: If NDT medications do not seem like a good fit for you, compounded T4/T3 products offer another alternative. Thyroid compounds are usually prepared in the same physiological ratio that is found in NDT products. However, physicians can elect to change the amount of T3 and T4, as compounding pharmacists must make the medications from scratch. This can be a huge advantage for patients who did not feel well on conventional treatments or natural desiccated thyroid treatments.

Whatever option you choose, be sure that your thyroid labs stay within the optimal reference ranges, and work with your practitioner to monitor them on an ongoing basis.
3. Eliminate Food Intolerances
I have found that most people with chronic disease will need to give up gluten, dairy, and soy, as they are the primary food sensitivities affecting people with chronic disorders. However, undergoing an elimination diet and food sensitivity testing will help you to pinpoint the foods that are problematic for you and lead to intestinal permeability, leaky gut.
4. Address Adrenals
Healthy adrenal hormones tame inflammation (including inflammation in the brain), and the most important strategy for combating adrenal hormone dysfunction is stress reduction. In the early stages of adrenal fatigue, the adrenals secrete excessive levels of cortisol; in the later stages, they secrete less and less, leading to inadequate levels of the anti-inflammatory hormone in the body. This can be a major contributing factor to brain fog.
Stress reduction, adequate sleep, taking the ABC’s (adaptogenic herbs, B vitamins and vitamin C) are great starting points for addressing adrenal hormone imbalances. Adrenotone is a formulation of adaptogenic herbs and vitamins that is designed to support stress levels and brain health, by promoting healthy cortisol levels and hypothalamic and pituitary function (HPA axis), as well as dopamine, norepinephrine, and epinephrine production. Taking three capsules per day can help with brain fog due to adrenal issues.
For additional ideas on how to reduce stress and support your adrenals, please take a look at my article on adrenal health.
5. Support Digestion
A lack of digestive enzymes and stomach acid are common in chronic disease, and can allow undigested food particles to enter the bloodstream through a leaky gut. This can often be the cause of food sensitivities and nutrient depletions, which can lead to brain fog (among other symptoms). I recommend using betaine with pepsin (Betaine HCL) and digestive enzymes, to help your body break down the foods you consume, so that they can be readily utilized by your body and reduce damage to your gut. Additionally, taking a quality probiotic can help restore the balance of bacteria in the intestines, and help prevent leaky gut.
My theory is that the body is focused on the backlog of undigested foods, instead of on creating luxuries like, brain power and energy.
6. Address Nutrient Deficiencies
Nutrient deficiencies can occur as a result of eating nutrient-poor foods, having inflammation from infections or food sensitivities, taking certain medications, or having an imbalance of gut bacteria. A lack of sufficient thyroid hormones can also lead to nutrient deficiencies, as it makes nutrient extraction from food more difficult and less efficient.
The nutrient deficiencies that we see with Hashimoto’s that can lead to brain fog include:

• Iron: Ferritin is our iron storage protein. Low levels are commonly associated with Hashimoto’s and may lead to fatigue, difficulty breathing, hair loss, and poor cognitive function. Ferritin levels should always be tested prior to supplementation, as it can build up in the body and become toxic at elevated levels. Ferritin level tests can be ordered by your doctor, or you can self-order one via Ulta Lab Tests. Normal ferritin levels for women are between 12-150 ng/mL. According to some experts, ferritin levels of at least 40 ng/mL are required to stop hair loss, while levels of at least 70 ng/mL are needed for hair regrowth. The optimal ferritin level for thyroid function is between 90-110 ng/mL. I recommend Ferrochel Iron Chelate.

• Folate: Vitamin B9 is a necessary nutrient that naturally presents itself as folate, which plays a vital role in the formation of DNA and cell growth. However, a MTHFR gene variation that is common for many with chronic disease, can impact how well your body metabolizes folate. Both folate and folic acid are forms of vitamin B9, required for numerous critical bodily functions. However, folic acid is synthetic, while folate occurs naturally in foods, such as broccoli, lamb, beets, and quinoa. Some people have a MTHFR gene variation that prevents them from properly processing the folic acid that may be present in certain supplements and processed foods. Some professionals claim this type of folic acid may even cause a build-up in the body, leading to toxicity, of which brain fog is a symptom. Likewise, the MTHFR gene produces an enzyme necessary to process vitamin B9 properly. This enzyme is also important for converting homocysteine to methionine, which the body needs for proper muscle growth, energy, and mental function. I recommend supplementing with Super Liquid Folate, which contains the natural form of folate.

• Vitamin B12: Low levels of B12 are commonly associated with Hashimoto’s and may lead to fatigue, depression, neurological issues, impaired digestion, brain fog, tingling extremities, nerve damage, seizures, and anemia. You can’t really overdose on B12, as it’s water-soluble, but I always recommend doing the initial test and retesting three months later to track and monitor your progress. You can test your B12 (cobalamin) levels through your healthcare provider or through Ulta Labs. Optimal B12 levels should be between 700-900 pg/mL. Please note: most labs will not flag low B12 levels unless they are under 200 pg/mL. I recommend supplementing with Vitamin B12 Lozenges (methylcobalamin) at a dose of 5000 mcg, sublingually, daily for 10 days; then 5000 mcg, once per week, for 4 weeks; then 5000 mcg monthly for maintenance. Be sure to use the sublingual version — swallowing B12 may result in inadequate absorption.

• Thiamine: Thiamine is one of the B vitamins, known as B1. Its main responsibility is to change carbohydrates into energy, and it also helps with the digestion of proteins and fats. Thiamine is necessary for proper release of hydrochloric acid in our stomachs, which is required for proper protein digestion. Most people with chronic disease have low stomach acid or do not release any stomach acid. Symptoms of milder forms of thiamine deficiency include fatigue, irritability, depression, and brain fog. Long-term thiamine deficiencies in those who consume any carbohydrates (even fruit) can lead to a buildup of pyruvic acid, which is a by-product of glucose metabolism, and can lead to mental fog.  

Tackling these steps will likely bring improvement — or even complete relief — of brain fog for many of you. As a reminder, please consult with your practitioner to determine which supplements and dosages are appropriate for you.
If you find that you are still experiencing symptoms, I recommend a few additional supplements that have been shown to support brain function. I will address these additional supplements tomorrow!! So Stay Tuned!!