I started a ketogenic diet for mental health. Why do I still feel so sick and still have symptoms?

When you start a ketogenic diet for mental health, you may be beginning the diet with several micronutrient deficiencies that developed prior to the diet. Highly processed food intake, psychiatric medications, poor health, substance abuse, and life stressors all deplete important B vitamins and thiamine in particular. Severe deficiencies in thiamine are not easily replenished with the ketogenic (or any healthy, micronutrient-rich diet). If you are recovering from a psychiatric disorder, your brain is using up nutrients like thiamine even faster, trying to repair existing damage. And so for people using the ketogenic diet to help heal their brain, thiamine and other micronutrient supplementation may be temporarily necessary for them to get the full benefit from the lifestyle change.

You don’t know why you are not feeling better. After all, you were told that keto for mental health was a great idea. You read the research and did your homework. But what you may not realize is that you might have come into your ketogenic diet with a stark deficiency in vitamin B1 (Thiamine) and that all the healing your brain is trying to do because of your ketogenic diet, may be in part responsible for your symptoms. The cure is not to stop your ketogenic diet. The cure is to supplement with additional micronutrients in a thoughtful way until your brain heals and stabilizes.

A thiamine deficiency can look like any of the following symptoms:

  • GERD
  • Bloating
  • Constipation
  • Gut Pain
  • Fatigue
  • Low carb/alcohol tolerance
  • Neuropathy/pain and tingling
  • Poor temp regulation
  • Dizziness
  • POTS/Visual Disturbances
  • Low/unsteady blood pressure
  • Tachycardia
  • Insomina
  • High/low appetite
  • Inability to gain weight
  • Raynauds/poor circulation
  • EMF and light hypersensitivity
  • Brain-fog and anxiety
  • Breathlessnes or air hunger
  • Sleep apnea

I am sure these all look familiar. Some of these symptoms may be what brought you to want to try to use the ketogenic diet to feel better. Some of these are symptoms that people blame the ketogenic diet for and then they stop before they can achieve its benefits.

If you still have a bunch of weird symptoms after using a well-formulated ketogenic diet and being consistent with your electrolytes, this might be due to thiamine deficiency.

But wouldn’t my well-formulated ketogenic diet fix a thiamine deficiency?

Yes, reducing the glucose intake in your diet has been fantastic for your thiamine levels. The more glucose we consume, the more thiamine we need. Thiamine is a cofactor for two important enzymes in glucose metabolism (pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase). So reducing our intake of glucose can be fantastic for helping us replenish and keep our stores for thiamine.

But thiamine is needed to digest protein and fats also. You can’t unlock all that fabulous fatty-acid energy you are taking in on a ketogenic diet without adequate thiamine to make several important enzymes.

You need thiamine to unlock the glucose your body makes (no need to eat any) to replenish glutathione. This happens through the Pentose Phosphate Pathway by the enzyme transketolase. Transketolase is a thiamine dependent enzyme. Meaning if you don’t have enough thiamine, you don’t have enough transketolase to do the things you need to be done. This can be a rate-limiting factor in your glutathione production. Glutathione is an essential endogenous (made by your body) molecule that acts as an anti-inflammatory. If you are trying to heal your brain and reduce and heal from neuroinflammation, you want your glutathione game to be on point.

Thiamine in this pathway is also used to generate/regenerate myelin sheaths. Myelin sheaths are used to insulate nerve cells and speed up the neuronal transmission of signals in the brain. And if you have had any level of neuroinflammation and oxidative stress, those myelin sheaths were under attack or just not able to keep up with a repair. Having adequate thiamine stores for this pathway and generating and repairing myelin sheaths are going to be vital in you healing your brain.

You need lots of thiamine to make enzymes to break down the protein you are getting from all that nutrient-dense red meat you are now consuming (hopefully). But you also need it for all the other meats. We need thiamine to make branched-chain alpha-keto acid dehydrogenase (BCKD) enzymes to break down the important amino acids leucine, valine, and isoleucine. These amino acids are used for energy metabolism, to help your brain make the cholesterol it needs to make repairs, and for neurotransmitter synthesis —all things you need to heal your brain after suffering from mental illness or neurological disorders.

If you do not have adequate thiamine, you will have trouble breaking your meat (protein) down into these amino acids. And if your body cannot break protein down because you do not have enough thiamine, it means it can’t use those amazing amino acid building blocks to help heal your brain. And I think we can all agree that would be tragic.

Your thiamine stores have to be fantastic to unlock all the goodness of a ketogenic diet. Alpha oxidation is a phase of fat oxidation and is needed to make Acetyl-CoA (ENERGY!) out of fat. And thiamine is a cofactor in the enzyme 2-Hydroxyacyl-CoA lyase (HACL) that your body uses to break down fat chains into smaller, usable pieces that your brain will then use to heal things that need repair.

Thiamine also plays a role in neurotransmitter balance. Yes, your ketogenic diet reduces inflammation, allowing the right environment for your brain to make neurotransmitters in and in the right amounts. But it also needs adequate thiamine to construct those neurotransmitters. In particular, acetylcholine, glutamate, and GABA. You may be a repeat visitor to the Mental Health Keto Blog and know the role of those neurotransmitters in certain mental illnesses. In that case, you know how important those are and how their imbalances contribute to symptoms.

Thiamine is also needed to regulate ion channels, which is a part of how your neurons communicate and take nutrients into the cells. It uses those nutrients and molecules to make the myelin sheaths we discussed earlier. Cells have to be able to communicate with one another to coordinate repairs. Any brain structures that have a particularly high rate of energy metabolism are going to burn through thiamine quite quickly. Those parts of the brain are the ones that regulate your nervous system at a very primal level. Components such as the brain stem, hypothalamus, mamillary body, and cerebellum are in charge of your autonomic nervous system. The autonomic nervous system controls two branches of the nervous system body temp, digestion, blood vessel dilation, etc. If you are thiamine deficient, your nervous system cannot adapt to environmental changes, and then you get a lot of odd and uncomfortable symptoms like the one listed above at the beginning of the post.

And while you are likely getting a lot of the thiamine you need to help heal your brain and to do all these things, there is a darn good chance you were deficient in one or more of the B vitamins going in (particularly thiamine).

Do you remember what your diet was before adopting a well-formulated ketogenic diet for mental illness and neurological disorders looked like? Was it daily, nutrient-devoid servings of foods that are part of the Standard American Diet (SAD) full of processed foods and highly processed carbohydrates? If so, you depleted your thiamine stores very badly, and you didn’t have what you needed to unlock energy and repair damage from neuroinflammation. That’s part of what caused the energy deficit in your brain in the first place, that wreaked havoc and caused all that damage you are now working to heal. And so it might be that for you to recover a bit faster or to feel the full benefits of a ketogenic diet sooner, you may benefit from some supplementation.

The need for thiamine is not about your calorie intake, although I suppose if you were eating very little food, that would help contribute to malnutrition. My point is you could be eating and even overeating calories, even calories coming from a ketogenic diet, and still not have sufficient thiamine to make the repairs to your brain that your body wants to accomplish on your behalf.

Were you on psychiatric medications prior to or still while on a ketogenic diet? Were you someone who was prescribed metronidazole (an antibiotic) and/or was sick a lot with viral and bacterial infections? Were you taking any diuretics? These deplete thiamine quite aggressively, and so you may have come into your healing diet from a place of deficiency or still shedding those vitamins because of your current medication intake as you are working to heal. And so this may be another reason why additional thiamine supplementation may make sense as you attempt to heal your brain using the ketogenic diet.

If you are on a ketogenic diet, you may still be enjoying coffee and alcohol. Or you may have had chronic alcohol use issues before you began the ketogenic diet, and you are using the ketogenic diet in order to treat alcohol use disorder. If that is the case, then you came into this diet HIGHLY thiamine depleted and likely starkly deficient. And so, if this is the case, you would benefit greatly from supplementation as you use the ketogenic diet to treat your mental illness and heal your brain.

Some people on ketogenic diets enjoy alcohol in moderation, and while I would not recommend alcohol consumption at all if you are working to heal your brain, I know that many people on keto enjoy their coffee. Coffee can also deplete thiamine because it has tannins and can deactivate thiamine in the gut. One or two cups of coffee a day are not generally problematic. But if you are trying to heal your brain and drinking a couple of pots a day, it might be. And maybe it still wouldn’t have been an issue if you hadn’t come in possibly being deficient in the first place.

Your gut may also not be done healing. Many people with mental illness and neurological issues suffer from significant gut issues that cause diarrhea. Gut issues can reduce your ability to absorb thiamine, and diarrhea means you are depleted further, as B vitamins like thiamine are water-soluble. So you may want to up your thiamine (and other B vitamin intake) while you are healing your gut at the same time that you are healing your brain using the ketogenic diet.

Now that you are on a ketogenic diet, do you find that your carbohydrate tolerance is very low? You may or may not have been insulin resistant if you are doing keto for your mental health. But keep in mind that experiencing very low carbohydrate tolerance may also be a sign of thiamine insufficiency. Because as you now know, thiamine is very much needed to break down glucose for fuel.

If you came into the ketogenic diet to treat your mental illness with an existing thiamine deficiency, you will only see some of the benefit you are actually capable of experiencing. And while a 50% improvement in your symptoms can feel like an absolute miracle that you are just so grateful for, I believe that you are entitled to get the full benefit of your hard work to heal yourself. If your thiamine deficiency is severe enough, there is a good chance that your ketogenic diet will not be able to overcome it. Knowing about thiamine deficiency and how supplementation can help heal your brain using a ketogenic diet is just one more way I think you have the right to know all the ways you can feel better!

If you want to supplement thiamine, you can attempt to do so with a good-quality methylated B-complex. Below are affiliate links and ones I recommend to clients using a ketogenic diet for mental health.

If you do not tolerate methylated B vitamins very well I like to use the following two supplements from Seeking Health. You will know you don’t tolerate methylated B’s well if you don’t feel well after taking them. They can make you feel agitated or can even cause headaches in some people. If you take these supplements below, you will need dietary sources of folinic acid to meet that need. I won’t go into it, but folate is its own whole separate thing deserving of another article.

Always take your Bs as part of a complex.

But if you are very thiamine deficient, you may need specialized supplements and some guidance on how to do that. And there is no better place to learn about thiamine deficiency and supplementation than the EONutrition Channel on YouTube.

So if you believe you are severely thiamine deficient and are suffering from one or more of the severe symptoms listed at the beginning of this post, I recommend you go there to learn more. You may need some additional supplements like magnesium and precursors to glutathione to be able to fix your thiamine deficiency and feel good doing it! All the information you could need can be found at EON Nutrition.

This blog post is one in a series about supplements that can help your brain heal while you are doing a ketogenic diet to treat your mental illness or neurological disorder (coming soon!)

You can learn more about me here. If you would like to learn more about my online program, where I teach people how to supercharge their ketogenic diet with personalized supplementation for optimal brain healing, you can learn more here:

I do use the EON Nutrition protocol for thiamine supplementation in my practice and my functional health coaching consultation.

I hope you have found this blog post to be helpful on your wellness journey.

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BCKDHB gene: MedlinePlus Genetics. (n.d.). Retrieved February 7, 2022, from https://medlineplus.gov/genetics/gene/bckdhb/

Chou, A., Clomburg, J. M., Qian, S., & Gonzalez, R. (2019). 2-Hydroxyacyl-CoA lyase catalyzes acyloin condensation for one-carbon bioconversion. Nature Chemical Biology, 15(9), 900–906. https://doi.org/10.1038/s41589-019-0328-0

Dhir, S., Tarasenko, M., Napoli, E., & Giulivi, C. (2019). Neurological, Psychiatric, and Biochemical Aspects of Thiamine Deficiency in Children and Adults. Frontiers in Psychiatry, 10. https://www.frontiersin.org/article/10.3389/fpsyt.2019.00207

EONutrition. (2020, April 5). Can a Ketogenic/Carnivore Diet Fix Chronic Thiamine Deficiency? Clinical Signs & Cases. https://www.youtube.com/watch?v=hGo-ZX5E-5M

Mega-Dose Thiamine: Beyond Addressing “Deficiency.” (n.d.). EONUTRITION. Retrieved February 7, 2022, from https://www.eonutrition.co.uk/post/mega-dose-thiamine-beyond-addressing-deficiency

Mifsud, F., Messager, D., Jannot, A.-S., Védie, B., Balanant, N. A., Poghosyan, T., Flamarion, E., Carette, C., Lucas-Martini, L., Czernichow, S., & Rives-Lange, C. (2022). Clinical diagnosis, outcomes and treatment of thiamine deficiency in a tertiary hospital. Clinical Nutrition, 41(1), 33–39. https://doi.org/10.1016/j.clnu.2021.10.021

Morell, P., & Quarles, R. H. (1999). The Myelin Sheath. Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th Edition. https://www.ncbi.nlm.nih.gov/books/NBK27954/

Neuroscientifically Challenged. (2015, September 11). 2-Minute Neuroscience: Myelin. https://www.youtube.com/watch?v=5V7RZwDpmXE


  1. Stacie Crochet says:

    Excellent article!

  2. Joey Evans says:

    Great tips regrading metronidazole . You provided the best information which helps us a lot. Thanks for sharing the wonderful information.

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