B1 Vitamin

B1 Vitamin also refers to as “Thiamin” which is a kind of water-soluble vitamin and belongs to the family of the vitamin B complex. It is naturally present in a variety of foods like poultry products, fortified cereals, nuts etc. and also available as a dietary supplement. Thiamin is a coenzyme of vitamin B1 that plays a significant role in metabolism, growth and proper functioning of the body cells.

Thiamin has a short half-life and less absorbed by the body, so it must be added into our regular diet. Its deficiency may cause diseases like Beriberi, Wernicke encephalopathy, Leigh syndrome etc.

Content: B1 Vitamin

  1. Definition
  2. Food Sources
  3. Dosage
  4. Absorption
  5. Dietary Supplements
  6. Thiamin Deficiency
  7. Functions
  8. Uses

Definition of B1 Vitamin

Vitamin B1 or Thiamin is a part of the vitamin B complex that exhibits properties like these are heat-labile and water-soluble. Thiamin is an active coenzyme of vitamin B1 complex that facilitates the metabolism of organic biomolecules through various biological pathways. It is also crucial for the functioning of the nervous and cardiovascular system.

PropertiesVitamin B1
Molecular formulaC12H17CIN4OS
Molecular weight300.81g/mol
Melting point164 degrees Celsius
SolubilityWater soluble
Half lifeShort
StabilityNon stable in neutral and alkaline solution

Food Sources Containing Thiamin

  • Vegetables: Cauliflower, potatoes, asparagus, kale, lettuce, spinach, tomatoes, squash etc.
  • Fruits: Oranges, apricots, watermelon, apples, etc. contains high vitamin B1 content.

Sources of vitamin B1

  • Poultry products: Mutton, pork, chicken, eggs etc.
  • Dairy products: Milk, curd, cheese etc.
  • Fortified grains and nuts: Rice, wheat, almonds, wall-nut etc.
  • Other sources: Brewer’s yeast and blackstrap molasses.

Dosage of B1 Vitamin

Recommended daily dosages of vitamin B-1 depends on various factors like age, gender and other condition like pregnancy. Recommended daily intake (RDI) for men and women are 1.2 mg/day and 1.1 mg/day, respectively. Pregnant women require a higher dose of vitamin B-1 while infants require lesser; both are based on the doctor’s prescription. If anyone is facing vitamin B-1 deficiency, then he/she must need to consume supplements which have more vitamins.


Small intestine actively consumes or absorbs the thiamin obtained naturally from the food source. Thiamin ingested in the form of dietary supplements are passively taken up by the small intestine.

The nutritional supplements are generally available in the phosphorylated form that is hydrolyzed by the intestinal phosphatase present in the small intestine to liberate free thiamin. After that, the free thiamin is primarily stored in the liver to a minimal extent, and the remaining is excreted out by the kidney in the form of urine.

Dietary Supplements

Vitamin B1 or thiamin can also be taken in the form of dietary supplement that is available in the form of a multivitamin or individual supplements. Thiamin monohydrate and thiamin hydrochloride are the two most common supplements that remain stable and water-soluble. Other than this, synthetic thiamin (Benfothiamin) is available in the form of dietary supplement that is absorbed by the body and transformed into free thiamin.

Thiamin Deficiency

Risk Factors

Vitamin B1 deficiency commonly occurs in the individuals like:

  1. Patients who are addicted to alcohol: Ethanol minimizes the gastrointestinal absorption of thiamin that results in lower absorption of thiamin and cause thiamin deficiency.
  2. Individuals with suppressed immunity: People suffering from malnutrition or having HIV infection get easily concurred with diseases like beriberi and Wernicke-Korsakoff syndrome.
  3. People taking concomitant use of multiple medications: This sometimes leads to cause toxicity and low absorption of vitamin B.
  4. Diabetic patients: These are at higher risk of getting thiamin deficiency by having type or type
  5. Patients who have undergone bariatric surgery lack vitamin B1, according to the RBC transketolase activity.

Signs and Symptoms

  • Weight loss
  • Confusion
  • Short term memory loss
  • Muscle weakness

Complications:  Vitamin B deficiency sometimes leads to cardiovascular disease like enlarged heart, disorders like Beriberi and Wernicke-Korsakoff syndrome.

Beriberi is a clinical condition where an individual acquires impaired sensory, motor and reflex functions. Generally, it is characterized by peripheral neuropathy, which sometimes results in congestive heart failure, edema and finally death of the person.

Wernicke-Korsakoff syndrome predominantly occurs in an individual having alcohol dependence, suppressed immunity and those who are suffering from gastrointestinal disorders. This disease involves two phases, namely acute and chronic phase.

The first stage also refers as Wernicke’s encephalopathy, while the second phase also refers as Korsakoff’s psychosis. The first phase is a life-threatening phase and causes peripheral neuropathy. People survived in the early stage may develop Korsakoff’s psychosis, which causes mental disorders like short term memory loss, disorientation and confabulation.


The following two assays can diagnose lack of vitamin B1:

Assaying of transketolase enzyme activity: The transketolase activity depends upon the thiamin pyrophosphate and the results obtained through this assay termed as “TDP or thiamin pyrophosphate effect“. The results are made by the extent of unsaturation of enzyme transketolase with the thiamin pyrophosphate.

In a healthy person, the TDP effect is between 0-15%. An individual with mild thiamin deficiency has 15-25% TDP effect. The individuals with a TDP effect of more than 25% confirms the lack of vitamin B1.

Assaying urinary thiamin excretion: Insufficient Vitamin B1 intake is observed in people excreting thiamin less than 100 mcg/day. Extremely low intake of vitamin B1 is observed when the individuals are excreting thiamin less than 40 mcg/day.


According to the WHO, administration of 10 mg thiamin for a weak can treat mild vitamin B1 deficiency. In case of severe deficiency, intravenous administration of 25-30 mg in infants and 50-100 mg in adults is usually recommended.

Then, it is followed by intramuscular administration of 10 mg daily for one weak. The recommended dose can vary with person to person, so it is advised to take prescription by a physician.

Functions of Thiamin

Metabolism of macronutrients: Thiamin combines with the energy molecule adenosine triphosphate to form thiamin pyrophosphate or TPP.
Thiamin pyrophosphate functions as an active cofactor that regulates the enzymatic activity of five enzymes, which participates in the catabolism of glucose, pyruvate, amino acids and lipids.

Boosts Immunity: Vitamin B1 releases some anti-stress agents during the time of low immunity or to withstand against stressful conditions.

Role in muscle tissue: TDP or thiamin diphosphate is an active metabolite that helps in muscle cell contraction and also regulates the conduction of nerve signals from one cell to the other.

Uses of Vitamin B1

Metabolic Disorders: Taking proper dosages of vitamin B-1 helps in the correction of metabolic disorder that is created due to genetic diseases like Leigh’s disease and maple syrup urine disease.

Brain Disorder: This brain problem is also termed as Wernicke-Korsakoff syndrome. The proper dose of vitamin B-1 reduces the risk of brain disorder, and it is often seen in alcoholic people.
Vitamin B-1 deficiency is usually found in alcoholic people, where 30%-80% of alcoholic people are suffering from this disorder. Separately thiamine shots are given during alcohol withdrawal period to reduce the risk of brain disorder.

Cataract: Higher consumption of vitamin B-1 with diet reduces the risk of cataract development.

Painful Menstruation: Proper intake of vitamin B-1 results in lesser pain during menstruation among girls aged between 12-21 years.

Kidney Disease: Patients already suffering from diabetes have a high risk of kidney disease due to insufficient intake of vitamin B-1. Taking 100 mg of vitamin three times a day for three months reduces albumin in body and albumin presence in urine indicates kidney damage.

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