Thiamine (Vitamin B1): A Potent Energy Booster and Anti-Beriberi!

Written by Angie Arriesgado
featured image for article on vitamin b1 thiamine

Today, we’re going to be covering the benefits of taking the first of the B vitamins – Vitamin B1, a.k.a Thiamine or Thiamin. Just a heads up, we’ll be using all 3 terms interchangeably throughout this article (they all mean the same thing). We’ll also give you an overview of the circumstances surrounding its discovery.

What is Thiamine?

More commonly known as Vitamin B1, Thiamine is a vitamin that helps with energy metabolism, cellular metabolism, and many other important functions in the body. It is considered an essential vitamin, meaning the body cannot make it on its own and will need to be taken via food or supplements. 

Only a small amount of vitamin B1 (approximately 30mg) is stored in the body, specifically in tissues like the heart, liver, brain, kidney, and skeletal muscles. Its half-life is estimated to be between 9-18 days, so it’s important to get this vitamin regularly, preferably on a daily basis (1).  

Vitamin B1 is included in the World Health Organization’s List of Essential Medicines (2). This list contains the medications and nutrients that are considered safe, effective, and essential for a health system.

How was Vitamin B1 discovered?

Vitamin B1 is found in a staple food that’s found in many countries – RICE. In the 19th century, rice milling became widespread. Eating “white” rice – with its husk, bran, and germ removed – became a popular diet trend in Japan.

Unfortunately, this switch from the healthier brown rice to polished white rice also caused a rapid acceleration in the number of beriberi cases (3). Beriberi makes walking difficult, causes a loss of feeling and muscle function, mental confusion, strange eye movements, nerve damage, and heart failure. The disease was so widespread it was considered endemic to Japan.  

Beriberi was also becoming a particular problem for Japanese sailors, you were dying of it in record numbers. It was initially thought to be an infectious disease, but the naval physician Kanehiro Takaki thought it had something to do with the sailors’ diet of nothing but white rice (yes, most of them ate ONLY white rice). He conducted a diet experiment where one group was fed only white rice, while the second group was fed a more nutritionally complete diet of white rice, barley, beans, meat, and fish.

Guess which group had zero cases of beriberi?

The second group, of course! Well, technically, there were 14 crew members who developed the disease, but Takaki soon found out that they didn’t follow the meal plan and secretly continued eating white rice only….

That being said, the most significant finding of Takaki’s experiment was in the white rice group – more than half of them suffered from beriberi! This was a significant discovery because it was the first step toward the eradication of beriberi in the navy – and the whole of Japan. Because of his discovery, Takaki was made a baron by the Japanese empire (4).

But it wasn’t until 1911 when Casimir Funk finally isolated thiamine from rice bran. He described it as the X-factor in preventing and treating beriberi (5). A few more decades went by before Robert Williams finally synthesized thiamine, which made it possible to fortify foods with thiamin around the world (6).  

vitamin b1 grains

What Does Thiamine Actually Do in the Body? 

In addition to its proven anti-beriberi benefits, here are some other benefits of adding more Vitamin B1 thiamine to your diet:

1)   Thiamine contributes to energy production

Thiamine helps convert carbohydrates into glucose. Thiamine is one of the 5 cofactors needed for the enzymes Pyruvate Dehydrogenase Complex and α-Keto glutarate dehydrogenase complex. Along with B2, B3, B5, and Lipoic acid, Thiamine is needed for both of these 2 enzymes to work.

Pyruvate Dehydrogenase complex is needed to turn sugar into energy. Glucose and Fructose (both sugars) can enter a process called glycolysis which occurs in the cytosol of the cell. Glycolysis leads to the production of Pyruvate. Once we have pyruvate, we can transport it into the mitochondria of our cells using special transportation enzymes and then combine the pyruvate with oxaloacetate to make acetyl-CoA.

Acetyl COA is the initial step of the ‘Krebs cycle’ or ‘CTA cycle’ that leads to the production of energy. α-Ketoglutarate dehydrogenase complex is the 4th major step of the Krebs cycle which turns alpha-Ketoglutarate into succinyl CoA. Of all the 5 main cofactors that are needed for these 2 enzymes, thiamine is the most likely to be deficient.

Pyruvate Dehydrogenase Complex, α-ketoglutarate dehydrogenase complex

Alpha-Ketoglutarate dehydrogenase complex is also used to change the branch chain amino acids, Valine, Leucine and IsoIsoleucine) into acetyl CoA and succinyl CoA so that they can also be used in the Krebs cycle to produce energy.

Myelin Sheaths

As we can see from the above diagram, Acetyl CoA is also necessary for the formation of myelin. Mylin is a fat-based molecule that surrounds the axons of nerve cells, which are the long thin parts of nerve cells that connect the two ends and transmit the electrical signals. The myelin provides insulation to the axons, and there are gaps between sections of the myelin. These gaps allow electrical impulses to jump down the axons between the gaps. This means signals can move along neurons, much more quickly than if there was no myelin sheath.

Diseases such as Multiple Sclerosis involve a reduced ability to produce myelin. And subsequently, the symptoms involve movement issues related to an inability to efficiently send nerve impulses to the muscles.

myelin sheaths, b1

Pentose Phosphate Pathway

The pentose phosphate pathway (PPP) is an incredibly interesting biochemical pathway that allows us to produce DNA and RNA as well as NADPH, which is used in the production of the body’s main antioxidant glutathione, as well as fatty acids, steroid hormones, neurotransmitters, and amino acids. It starts off at the same starting point as glycolysis, with glucose being turned into glucose-6-phosphate as was shown in the diagram below.

However, in the PPP, glucose-6-phosphate dehydrogenase takes glucose-6-phosphate and runs it down a different biochemical pathway. About 5%-10% of the glucose in the body is used in this pentose phosphate pathway (7) instead of glycolysis, and thiamine is needed for one of the later key enzymes in the pathway called transketolase. A deficiency in Thiamine can lead to problems in running this pathway and the efficient production of DNA/RNA, glutathione, fatty acids, steroid hormones, neurotransmitters and amino acids.

Supplementation with a fat-soluble version of thiamine called Benfotiamine is now being recommended for some diabetics to supplement with to support the disposal of sugar down the PPP pathway. Benfotiamine offers better absorption by the brain and central nervous system and can increase body stores of B1. This potentially means that diabetics can more efficiently run the PPP and use up excess glucose, reducing blood sugar levels (8).

pentose phosphate pathway and b1


Thiamine is also involved in preventing the formation of oxalate crystals in the body. Oxalate crystals are best known when they combine with calcium to form calcium oxalate which can then form kidney stones. However, as scientific knowledge has grown, it’s also now known that oxalate crystals can form not just in the kidneys, but across the body. They are also linked to a huge range of chronic health conditions such as arthritis, chronic fatigue, autoimmunity, and pancreatitis (9, 10).

oxalate crystals, high oxalates

2) Vitamin B1 promotes insulin sensitivity

Research studies have shown that there is a relationship between diabetes and thiamine levels. Compared to healthy individuals, diabetics have lower thiamine levels as evidenced by these statistics (11, 12):

  • Type 1 diabetics – 76% lower thiamine levels
  • Type 2 diabetes – 50-75% lower thiamine levels

Fortunately, increasing thiamine dosage may help manage diabetic symptoms. One small study discovered that giving 100mg thiamine supplements 3x a day for 90 days reduced the severity of symptoms in type 2 diabetics who were also diagnosed with microalbuminuria (13).

3) Thiamine supports optimal heart health

Thiamine also contributes to the normal function of the heart (14). A deficiency of this essential nutrient can lead to congestive heart failure.

A systematic review on 2 randomized, double-blind, and placebo-controlled trials reported that thiamine supplementation helped improve the left ventricular ejection fraction (LVEF) in patients with congestive heart failure (15).

LVEF measures how much blood is being pumped out of the heart’s left ventricle with each pump/contraction. Simply put, patients with congestive heart failure have less than normal ejection fraction rates. Normal LVEF rates range from 55 to 70% (16).

In addition to improving LVEF, thiamine supplementation can also help improve cardiac function, especially in patients with heart failure (17).

4) Vitamin B1 supports brain health

Because B1 is needed for energy production, glutathione, fatty acids, steroid hormones, neurotransmitters, and amino acids the brain is highly vulnerable to vitamin B1 deficiency.

Here are a few conditions where thiamine supplementation has been shown to help:

Wernicke-Korsakoff Syndrome (WKS)

Excessive alcoholism can prevent B1 absorption, thus leading to severe thiamin deficiency. Alcoholism is the main risk factor for a rare type of brain disorder known as Wernicke-Korsakoff syndrome (WKS). WKS starts out as Wernicke encephalopathy (WE), which can progress to Korsakoff’s psychosis if left untreated. WKS signs and symptoms include (18):

  • Double vision
  • Loss of muscle coordination
  • Confusion
  • Memory loss
  • Difficulties in communicating
  • Hallucinations

So, can thiamine supplementation help with WKS?

According to a 2017 study, high-dose thiamine is a safe and effective treatment option. Researchers administered at least 500mg of intravenous thiamine to a small group of patients (n=11) with suspected Wernicke encephalopathy. After a few days (median is 3 days), 8 out of 11 patients showed significant improvements in their WE symptoms (19).

Stroke patients

When the blood supply to the brain is cut off, a stroke occurs. It affects vision, speech, and movement. Another poststroke effect is fatigue, which isn’t always improved with rest (20). But thiamine supplementation might help!

In one case study, 3 stroke patients suffering from poststroke fatigue were given a high dose of thiamine. Two patients were given 600mg/day orally and the third patient was given 100mg/week parenterally. The researchers observed a significant reduction in all 3 patients’ fatigue levels after supplementing with thiamin for several months (21).  

Neurodegenerative conditions

Vitamin B1 therapy offers neuroprotection and helps slow down the advance of neurodegenerative diseases like Alzheimer’s, Parkinson’s, and Huntington’s (22).

Patients suffering from Alzheimer’s have reduced levels of thiamine in the brain. The activity of thiamin-dependent enzymes also slows down. However, the good news is that thiamin supplements may help improve cognitive function, especially in younger patients. Unfortunately, elderly patients have naturally lower vitamin B1 absorption rates because of their age, so higher doses are recommended. Studies suggest an initial dosage at 100mg 2-3 times a day for at least 1-2 weeks (23).

Parkinson’s is another common neurodegenerative condition amongst older individuals. According to Luong and Nguyen, thiamine induces the release of dopamine, and Parkinson’s is associated with a reduction of Dopamine releasing neurons in the Substantia Nigra part of the brain. They also found that thiamine was able to improve Parkinson’s symptoms as well (24).

What are the best food sources of Thiamine?

To ensure you meet the required daily allowance for Vitamin B1 (please refer to the next section), consider eating more of these thiamin-rich foods (25):  

infographic showing the best sources of Thiamin or Vitamin B1

What’s the best Vitamin B1 Thiamine dosage?

Here’s the recommended daily allowance for adults:  

  • RDA for men 19 years old and above: 1.2mg
  • RDA for women 19 years old and above: 1.1mg
  • RDA for pregnant and lactating women: 1.4mg

Is there an upper limit?

To date, no upper limit for thiamine has been set. B1 is considered safe and nontoxic. No reports of bad effects from high doses have been noted so far (26).

Final words

Thiamine is one of the ingredients in our Seneca Nootropic complex. Each serving of Seneca contains 1.2mg of Thiamine hydrochloride. This dose is sufficient to complement the health benefits of the other B vitamins (B2, B3, B6, B9, and B12) as well as the 12 nootropic compounds present in Seneca.

To know more about nootropics, click here to read our article on “What are nootropics and cognitive enhancing supplements?”  


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