Vitamin B1 (Thiamine): Benefits, Levels, and Deficiency Symptoms

Vitamin B1 (thiamine) is essential for energy production and nervous system function. Normal levels range from 70 to 180 nmol/L. Low levels indicate vitamin B1 deficiency symptoms such as fatigue and neuropathy, while high levels usually reflect supplementation. Maintaining proper thiamine levels supports metabolism and brain health.

Contents

→ Result interpretation
→ Check your value Vitamin B1
→ What is Vitamin B1
→ Reference ranges
→ Causes of abnormal values
→ Vitamin B1 in combination with other markers
→ Possible symptoms
→ When to see a doctor
→ What to do if abnormal
→ Frequently asked questions
→ Related markers

Result interpretation Vitamin B1

What your result means based on common reference ranges

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Normal

Vitamin B1 levels within range support normal energy metabolism and healthy neurological function without signs of deficiency.

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Mildly elevated

Mildly elevated Vitamin B1 levels usually reflect recent supplementation or fortified food intake without clinical toxicity risk.

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Significantly elevated

Significantly high Vitamin B1 levels are typically linked to intravenous therapy or excessive supplementation, not metabolic disease.

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Below normal

Low Vitamin B1 levels indicate deficiency affecting glucose metabolism, often associated with neuropathy or cardiovascular dysfunction.

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Vitamin B1, nmol/L

Sex

Age

What is Vitamin B1?

Vitamin B1 plays a key role in converting carbohydrates into usable energy and supporting nerve conduction. It acts as a cofactor in glucose metabolism and is critical for brain and cardiovascular function. A blood test for Vitamin B1 helps assess nutritional status and detect deficiencies linked to conditions like malnutrition, alcoholism, and malabsorption syndromes. Low levels can impair energy production and lead to neurological disorders, while elevated levels are typically related to supplementation rather than disease. Monitoring Vitamin B1 levels is important in patients with chronic illness, digestive disorders, or unexplained fatigue.

Reference ranges

Group	Normal range	Unit
Men	70 – 180	nmol/L
Women	70 – 180	nmol/L
Children	70 – 180	nmol/L
Elderly	70 – 180	nmol/L

Causes of abnormal values

Causes of low Vitamin B1

• Chronic alcohol use: impairs intestinal absorption and increases renal loss of thiamine
• Malabsorption syndromes: conditions like Crohn's or celiac disease reduce nutrient uptake
• High-carbohydrate diet: increased metabolic demand depletes thiamine stores
• Diuretic use: increased urine output accelerates loss of water-soluble vitamins
• Dialysis: removes circulating thiamine during blood filtration

Causes of high Vitamin B1

• Oral supplementation: intake of B-complex vitamins increases circulating thiamine levels above baseline
• Intravenous therapy: direct bloodstream delivery bypasses absorption limits and elevates levels rapidly
• Fortified foods: enriched cereals and grains increase daily thiamine intake significantly
• Recent meal intake: postprandial rise causes temporary elevation without clinical significance
• Reduced kidney clearance: impaired filtration prolongs circulation of water-soluble vitamins
• High-dose supplementation: excessive intake exceeds metabolic requirements

Vitamin B1 in combination with other markers

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Low Vitamin B1 + High Lactate Impaired aerobic metabolism causes lactic acidosis due to disrupted glucose oxidation pathways.

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Low Vitamin B1 + Low Magnesium Magnesium deficiency blocks thiamine activation, worsening metabolic dysfunction and neurological symptoms.

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Low Vitamin B1 + High MCV Suggests chronic alcohol use affecting red blood cells and nutrient absorption simultaneously.

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Low Vitamin B1 + High Glucose Indicates impaired carbohydrate metabolism contributing to energy deficiency and metabolic imbalance.

Possible symptoms

•Fatigue and low energy
•Peripheral neuropathy (tingling, numbness)
•Muscle weakness
•Mental confusion or memory issues
•Rapid heart rate or palpitations

When to see a doctor

Consult a doctor if Vitamin B1 levels fall below 70 nmol/L or symptoms like numbness, fatigue, or confusion persist. Seek medical advice if you have alcohol use history, digestive disorders, or worsening neurological signs.

What to do if abnormal

🥩 Increase intake of thiamine-rich foods like pork, legumes, and seeds
🚫 Reduce alcohol consumption to improve absorption
💊 Review supplements and adjust dosage if levels are abnormal
🍬 Limit refined sugar intake to reduce metabolic demand
🩺 Discuss medications like diuretics with a healthcare provider

The information on this page is intended for general understanding of test results and does not replace medical consultation. Accurate interpretation requires considering other blood markers and individual factors.

Content is based on medical literature and used within the PulseBook analytical system.

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Frequently asked questions

What is a normal Vitamin B1 level?

Normal Vitamin B1 levels range between 70 and 180 nmol/L (15–50 ng/mL). This range reflects adequate thiamine availability for energy metabolism and nervous system function. Values within this range indicate proper nutritional status and metabolic balance.

What are vitamin B1 deficiency symptoms?

Vitamin B1 deficiency symptoms include fatigue, confusion, neuropathy, and muscle weakness. These occur because thiamine is essential for energy production and nerve function. Severe deficiency can affect the heart and brain, especially in cases of malnutrition or alcohol use.

What are the benefits of vitamin B1?

Vitamin B1 benefits include supporting energy production, maintaining nerve health, and aiding carbohydrate metabolism. Thiamine benefits also extend to cardiovascular function and brain performance, making it essential for overall metabolic health.

What causes high levels of Vitamin B1 in blood?

High Vitamin B1 levels are usually caused by supplementation, fortified foods, or IV therapy. This is not typically harmful because thiamine is water-soluble and excess amounts are excreted in urine rather than stored in the body.

What is the Vitamin B1 normal range in ng/mL?

The Vitamin B1 normal range in ng/mL is approximately 15–50 ng/mL. This corresponds to 70–180 nmol/L and is used depending on laboratory measurement units. Both ranges reflect adequate thiamine status.

What does high Vitamin B1 mean?

High Vitamin B1 levels usually indicate recent intake of supplements or enriched foods rather than disease. It reflects intake exceeding immediate metabolic needs and is generally not associated with toxicity.

What is Vitamin B1 plasma normal range?

The Vitamin B1 plasma normal range is similar to whole blood, typically around 70–180 nmol/L depending on the laboratory method. Plasma measurements may vary slightly but serve the same diagnostic purpose.

What depletes Vitamin B1 in the body?

Alcohol, high sugar intake, diuretics, and malabsorption conditions deplete Vitamin B1. These factors either reduce absorption or increase excretion, leading to deficiency and metabolic dysfunction.