Vitamin B1 — thiamine

Role of Vitamin B1 (Thiamine) in the Body

Vitamin B1 (thiamine) is a water-soluble vitamin that plays a key role in energy metabolism and nervous system function.

Main functions:

1. Energy metabolism – participates in the metabolism of carbohydrates, proteinsProteins are high-molecular organic substances consisting of alpha-amino acids linked in a chain by a peptide bond. In living organisms, the amino acid composition of proteins is determined by the genetic code. During synthesis, 20 standard amino acids are used in most cases. Many combinations of them determine the great diversity of properties of protein molecules. Proteins play a key role in the immune response and can perform transport, storage, catalytic, structural, and receptor functions. Proteins are an important part of the nutrition of animals and humans. The main sources of proteins are meat, poultry, fish, milk, nuts, legumes, and grains., and fats, helping convert them into ATP (energy).
2. Nervous system – supports neuron function, participates in nerve impulse transmission.
3. Cardiovascular system – regulates vascular tone and heart muscle function.
4. Digestion – promotes normal gastric juice secretion and intestinal peristalsis.

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Symptoms of Vitamin B1 Deficiency

Thiamine deficiency (hypovitaminosis B1) can lead to serious disorders, especially with chronic deficiency.

Early signs:

• Fatigue, irritability
• Decreased appetite, nausea
• Memory and concentration impairments
• Muscle weakness, cramps

Severe forms of deficiency:

1. Beriberi (disease associated with B1 deficiency):

• Dry form – nervous system damage (polyneuritis, paresis, coordination disorders).
• Wet form – edema, heart failure, tachycardia.

1. Wernicke-Korsakoff syndrome (in alcoholism):

• Wernicke’s encephalopathy (confusion, nystagmus, ataxia).
• Korsakoff’s psychosis (memory loss, confabulations).

Risk groups:

• Alcoholics (ethanol impairs B1 absorption)
• People with unbalanced nutrition (e.g., excess refined carbohydrates)
• Patients with gastrointestinal diseases (malabsorption)
• Pregnant and breastfeeding women

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Symptoms of Vitamin B1 Excess

Thiamine overdose is rare, as it is water-soluble and excreted in urine. However, with injectable administration, the following are possible:

• Allergic reactions (urticaria, anaphylaxis)
• Headache, tachycardia
• Impaired liver and kidney function (with extremely high doses)

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Normal Vitamin B1 Levels in Blood

Thiamine in blood is usually measured in nmol/L or ng/mL. Reference values may vary between laboratories, but on average:

• Whole blood: 70–180 nmol/L (≈ 2.1–5.4 μg/dL)
• Plasma: 8–30 ng/mL

Note: B1 testing does not always reflect its actual level in tissues, so transketolase activity (a thiamine-dependent enzymeEnzymes are proteins that accelerate chemical reactions in the body. They ensure the occurrence of metabolic processes such as food digestion, energy release, cell formation, and many others.) is often assessed.

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Conclusion

Vitamin B1 is critically important for energy and nervous system function. Its deficiency leads to severe disorders, while excess is rare.