Facts About Vitamin B1 (Thiamine)

Vitamin B1 Thiamine

There are many vitamins in the human body, but Vitamin B1 is considered to be among the most critical. It is essential for the proper functioning of the nervous system, the brain, the heart, and the muscles.

Vitamin B1 is also referred to as Thiamine or Thiamin. It is a member of the B vitamin complex.

Vitamin B1 Functions

Thiamine, or vitamin B1, was the first of the B vitamins to be discovered. As a catalyst, it enables the decarboxylation of branched-chain amino acids and alpha-ketoacids to generate energy. In the form of thiamine pyrophosphate, it functions as a coenzyme for transketolase reactions.

Additionally, thiamine is suspected of contributing to the transmission of nerve impulses and the maintenance of myelin sheath.

Vitamin B1 Benefits

Protect Nerves

Vitamin B1 is an essential nutrient because it helps in the proper formation of the myelin sheath around nerves. There is a possibility that insufficient amounts of this vitamin can lead to degeneration of the coverings of the nerves and cause death as well as nerve damage.

Protect The Heart

You need vitamin B1 to make acetylcholine, a neurotransmitter. In addition to relaying messages between the nerves and muscles, this neurotransmitter is essential to ensuring that the heart is functioning properly. A deficiency of vitamin B1 might result in irregular heart functions. People suffering from congestive heart failure who were given intravenous vitamin B1 for seven days showed clear improvements in their echocardiograms after taking it.

Energy Production

Our bodies rely heavily on sugars as the primary source of energy. Because of vitamin B1, sugar is oxidized and converted to a form of energy which can be used. Vitamin B1 functions as a component of the pyruvate dehydrogenase system, which is a complex enzyme system that produces energy for the body.

Dementia Prevention

There is evidence that vitamin B1 may slow down the progression of Alzheimer’s disease. In both cases of thiamine deficiency or Alzheimer’s disease, cognitive problems were found, as well as issues with brain glucose metabolism. The patients in both instances reported they felt significantly better when they were receiving vitamin B1 supplements. Current research studies using placebo-controlled trials are being carried out in order to identify more information about the mechanism by which this happens.

Anti-aging Properties

Taking vitamin B1 will protect you against the signs of aging by acting as a powerful antioxidant.

Improved Digestion

This vitamin also plays a major role in the production of hydrochloric acid for digestion, which is vital for a complete digestion and absorption of food.

Prevents Cataracts

Cataracts can be delayed or prevented by the use of vitamin B1.

Increase Red Blood Cells

Getting enough vitamin B1 is critical for making red blood cells (RBC).

Improved Memory

In addition to its ability to improve the nervous system, vitamin B1 has a positive influence on the mind. A variety of nerve disorders, such as multiple sclerosis, Bell’s palsy, and age-related neuropathy are managed using this B vitamin. Studies have shown that it has the ability to help improve memory and concentration.


A healthy amount of vitamin B1 is able to stabilize and guard against the deficiency caused by cirrhosis, infections, hyperthyroidism, and the other effects of alcoholism.

Recommended Vitamin B1 (Thiamine) Dosage

Below is a table showing the recommended dietary allowances (RDA) for Vitamin B1 broken down by age and sex.

Birth to 6 months0.2 mg0.2 mg
7 to 12 months0.3 mg0.3 mg
1 to 3 years0.5 mg0.5 mg
4 to 8 years0.6 mg0.6 mg
9 to 13 years0.9 mg0.9 mg
14 to 18 years1.2 mg1.0 mg
19 to 50 years1.2 mg1.1 mg
51+ years1.2 mg1.1 mg
RDA for Thiamine

Vitamin B1 (Thiamine) Deficiency

The term “thiamine deficiency” is the term used to describe a state where the body does not have sufficient amounts of thiamine. There are several possible causes for thiamine deficiency, including a lack of thiamine in the diet, medications, or other health conditions.

The lack of thiamin can produce symptoms such as irritability, fatigue, and a decrease in appetite. Keeping thiamin deficiency at bay requires the consumption of a variety of thiamin-containing foods and, possibly, the addition of a thiamin supplement as part of an overall health program. If the condition has been detected using reliable lab tests, it can be treated with a high dose of supplementation.

Industrialized countries have a lower risk of developing thiamin deficiency because people have more regular access to foods that contain the thiamin that is required for their health. In spite of this, there are some groups of people that are more susceptible than others. These groups include pregnant women and people with an overactive thyroid because these groups need more of this nutrient due to their higher requirements.

World map showing prevalence of Thiamine deficiency.
World map showing prevalence of Thiamine deficiency. Map part of journal article titled Thiamine fortification strategies in low- and middle-income settings: a review


It is a fact that most deficiencies occur as a result of inadequate dietary intake. Thiamine deficiency can also be caused by factors such as low absorption of the vitamin or an increase in its excretion from the body.

The following is a list of some of the most common causes of Thiamin deficiency.

  • A diet that is deficient in Thiamin
  • Anorexia Nervosa
  • A diet high in processed carbohydrates
  • Alcoholics
  • HIV
  • Medications
  • Hyperthyroidism
  • Pregnancy
  • Breastfeeding
  • Exercise
  • Fever
  • Liver diseases
  • Diarrhea

Who Gets Vitamin B1 Deficiency?

Despite being an essential nutrient, thiamin is not always available in sufficient quantities. Among the most likely groups to suffer from inadequate thiamin status are the following.


The most common cause of thiamin deficiency in highly industrialized countries appears to be chronic alcohol use disorders. There is evidence that as many as 80% of people who have chronic alcoholism are deficient in thiamin. It is due to the fact that alcohol decreases the absorption of thiamin in the gastrointestinal tract. In addition, it decreases the amount of thiamin stored in the liver, and the phosphorylation of thiamin in the body. People who are suffering from alcoholism also tend to be insufficiently nourished with essential nutrients, such as thiamin.

AIDS & HIV Patients

It has been found that HIV-infected people are especially at risk for thiamin deficiency and its sequelae, such as beriberi and Wernicke-Korsakoff syndrome. It is likely that malnutrition is responsible for the association between thiamin deficiency and HIV/AIDS.

Elderly and Geriatric Population

There is evidence that as many as 20% to 30% of older adults may have thiamin deficiency. The reasons for this may include health problems such as low dietary intakes, chronic diseases such as diabetes, or polypharmacy which is the use of multiple medications. Another factor may be the difficulty in absorbing Thiamine. When we age, we naturally experience a decline in how well we absorb thiamine.

Bariatric Surgery

Thiamine deficiency is more common among people who have had bariatric surgery due to malabsorption issues. Depending on how impaired your absorption is, you may develop beriberi or Wernicke’s encephalopathy. There is almost always a recommendation for the use of thiamin-containing supplements after surgery.


There are studies that suggest that the levels of Thiamin in the plasma of people with type 1 diabetes are up to 76% lower than those of healthy volunteers. It has also been observed that type 2 diabetics have a 50% to 75% lower Thiamine level compared to those without diabetes. There is a hypothesis that people with diabetes have decreased levels of Thiamine in their system as a result of increased clearance by the kidneys.

Signs & Symptoms of Vitamin B1 Deficiency

In its early stages, thiamin deficiency can cause numerous signs and symptoms, including but not limited to. Weakness and anorexia, confusion, forgetfulness, and other mental symptoms; muscle weakness; impotence; and cardiovascular symptoms like an enlarged heart are just some of the many signs and symptoms that may accompany a Thiamin deficiency.


Thiamin deficiency is most often characterized by beriberi, a form of neuropathy characterized mainly by wasting and peripheral neuropathy. Patients suffering from the condition have impaired motor, sensory, and reflex abilities. Beriberi can sometimes lead to congestive heart failure, but this is a rare occurrence.

It seems that beriberi is relatively rare in developed countries; however, this condition does occasionally occur within those countries. Treatment with thiamine supplements often cures the condition fast.

Wernicke-Korsakoff syndrome

The Wernicke-Korsakoff syndrome is one of the most common manifestations of thiamin deficiency in developed countries. It is estimated that people with chronic alcoholism are 8 to 10 times more likely to be afflicted by this disorder than the general population. Another population at risk include drug addicts, people suffering from AIDS, and those suffering from gastrointestinal problems.

There are two phases to Wernicke-Korsakoff syndrome. A first acute stage of the disease is called Wernicke’s encephalopathy, and it can cause peripheral neuropathy. About 20% of patients with Wernicke’s encephalopathy will die without treatment. Korsakoff’s psychosis will develop in those who do not die. This is the second phase, which results from chronic Thiamine deficiency. This condition is often accompanied by severe disorientation, short term memory lapses and confusion.

Vitamin B1 (Thiamine) Toxicity

Taking too much thiamine doesn’t cause any toxicity. This vitamin has no upper limit and therefore there is no problem with taking too much of it. Since it is water soluble, and therefore is easily excreted in the urine by the body, it will simply be disposed of in the urine.

Nevertheless, you may experience digestive distress as a result of ingesting large amounts. Synthetic forms of vitamin B1 such as thiamine hydrochloride may cause allergic reactions and other side effects. For instance, abdominal pain, arrhythmia, irritated eyes, vomiting and diarrhea are just a few of the symptoms that one may get.

The drug does not have any known toxicity, however, it can cause interactions with certain medications, such as furosemide and fluorouracil. It is recommended that you consult your doctor prior to starting any Thiamine supplement as there is a possibility that it might interact with other medications you are taking.

Sources Of Vitamin B1 (Thiamine)

You can get vitamin B1 from a variety of whole foods as well as processed foods. According to recent research, most North Americans receive their daily thiamin intake from cereals and bread, pork, dairy products, whole grains, legumes, wheat germ, bran, brewer’s yeast and black strap molasses.

Plant Sources

  • Rice
  • Breakfast Cereals
  • Black Beans
  • Bread
  • Flour
  • Pasta
  • Orange Juice
  • Sunflower Seeds
  • Oatmeal
  • Corn
  • Barley
  • Apple

Non Plant Sources

  • Pork/ham
  • Fish
  • Mussels
  • Beef
  • Milk
  • Yogurt
  • Cheese
  • Chicken

Among all of the B vitamins, vitamin B1 is the most dependent on the other B vitamins. In the absence of enough folic acid, vitamin B6 and vitamin B12, thiamine cannot be absorbed correctly, and in the absence of enough vitamin B12, there can be more thiamine loss through the urine. The presence of vitamin B6 appears to assist in the distribution of thiamine throughout the body.

In most cases, people do not require supplements of this vitamin since it is easy to get enough of it through their diet. Despite this, since thiamine does not have a toxic level of intake, taking an additional amount of it in supplements is not harmful and might even be beneficial.

The information present in this article is not intended in anyway to be taken as medical advice. Always consult a doctor prior to making any medical decisions or taking any supplements.