Why is thiamin called the energy-releasing vitamin?

Thiamin plays a direct role in the conversion of carbohydrates into usable cellular energy. Specifically, thiamin pyrophosphate (TPP) is a coenzyme for pyruvate dehydrogenase — the enzyme complex that converts pyruvate (produced from carbohydrate breakdown) into acetyl-CoA, which then enters the citric acid cycle to produce ATP. Without adequate thiamin, this critical step in energy production is impaired. This is why EFSA recognises that thiamin contributes to normal energy-yielding metabolism.

What is the NRV for thiamin and how much do you provide?

The EU Nutrient Reference Value (NRV) for thiamin (vitamin B1) is 1.1 mg per day. Our Vitamin B Complex provides exactly 1.1 mg of thiamin hydrochloride per serving — 100% NRV. Thiamin requirements can increase with higher carbohydrate consumption, alcohol intake, and during pregnancy and breastfeeding. As a water-soluble vitamin, thiamin is not stored in large amounts — the body holds only about 30 mg total, lasting approximately 14–20 days without intake.

What foods are naturally rich in thiamin?

Thiamin is found in a wide variety of foods, though often in modest amounts. The richest sources include whole grains and fortified cereals, pork, fish (particularly trout and tuna), legumes (beans, lentils), seeds (sunflower seeds), nuts (macadamia, pecans), and yeast extracts. However, thiamin is sensitive to heat and can be lost during cooking (up to 50% loss). Additionally, some food processing methods like the milling of white rice and white flour remove thiamin-rich components. This is why many countries mandate the enrichment of refined flour products with thiamin.

Can alcohol affect thiamin levels?

Yes — alcohol consumption can significantly affect thiamin status. Alcohol impairs thiamin absorption in the gut, reduces thiamin storage in the liver, and increases thiamin excretion through urine. Additionally, people who consume alcohol regularly may have diets lower in thiamin-rich foods. Even moderate regular alcohol consumption can impact thiamin status over time. This is one reason why B-complex supplementation is commonly recommended for those who regularly consume alcohol. Our B Complex provides 100% NRV of thiamin to help maintain adequate levels.

Ingredient Deep Dive · Thiamin (Vitamin B1)

Ingredient Thiamin

Vitamin B1 — the energy-releasing vitamin for heart and nerve function.

Thiamin hydrochloride is the stable, well-absorbed form of vitamin B1. Found in our Vitamin B Complex, it supports normal energy metabolism, heart function, and nervous system health.

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What is Thiamin?

Thiamin (vitamin B1) is the first B vitamin to be discovered and is a water-soluble vitamin essential for energy metabolism. Its biologically active form, thiamin diphosphate, serves as a coenzyme for several key enzymes in carbohydrate metabolism, including transketolase, pyruvate dehydrogenase, and α-ketoglutarate dehydrogenase. These enzymes are central to the conversion of food into cellular energy via the Krebs cycle — the metabolic pathway that generates the majority of the body's ATP.

Thiamin is particularly important for tissues with high energy demands, including the heart, brain, and nervous system. The nervous system depends entirely on glucose for its energy supply, and thiamin is required for glucose metabolism. Even a mild thiamin deficiency can impact neurological function and psychological well-being. Because thiamin is water-soluble and not stored in significant amounts, regular dietary intake is essential to maintain adequate levels.

EFSA-approved health benefits

The European Food Safety Authority (EFSA) has confirmed that thiamin:

contributes to normal energy-yielding metabolism
contributes to the normal functioning of the nervous system
contributes to normal psychological function
contributes to normal heart function

Why we use Thiamin in Nutri-Leaf formulas

Nutri-Leaf Vitamin B Complex provides 1.1mg of thiamin per capsule (100% NRV) alongside the seven other essential B vitamins in a comprehensive once-daily formula. The B Complex uses active, bioavailable forms of B vitamins throughout, ensuring that the body can utilise each nutrient without requiring additional metabolic conversion steps.

Products containing Thiamin

The Nutri-Leaf product featuring thiamin is Vitamin B Complex, which provides all eight B vitamins at 100% NRV per capsule in active, bioavailable forms for comprehensive energy and nervous system support.

Learn more about the role of B vitamins in energy metabolism on our Energy & Vitality and Stress Management health guides. Visit the Ingredient Philosophy page for our approach to B vitamin formulation.

Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle.

Ingredient profile

Thiamin — the original B vitamin, essential for energy and nerves.

What it is
Thiamin (vitamin B1) is the first B vitamin to be discovered and is a water-soluble vitamin essential for energy metabolism. Nutri-Leaf Vitamin B Complex provides it at 100% NRV per capsule.
Why we use it
Every ingredient in our formulas serves a specific nutritional purpose. What you see on the label is exactly what’s in the capsule.
German quality sourcing
All ingredients are sourced to meet German and EU pharmacopoeia quality standards, then manufactured into finished supplements in Germany by an FSSC 22000 certified food-supplement producer.
Benefits & research
Role in the body
Thiamin contributes to normal energy-yielding metabolism, the normal functioning of the nervous system, normal psychological function and normal heart function.
Approved health claims
According to the European Food Safety Authority (EFSA), thiamin contributes to normal energy-yielding metabolism, the normal functioning of the nervous system, normal psychological function and normal heart function.
EU quality standards
Nutrient Reference Values (NRVs) are set by EU Regulation 1169/2011. Our formulas are designed to provide meaningful percentages of these reference values per daily serving.

Nutri-Leaf formulas featuring this ingredient

Supplements containing Thiamin (Vitamin B1).

Vitamin B Complex

Nutri-Leaf

Vitamin B Complex

1 capsule per dayHPMC vegetable capsule

~~€18,99~~€14,11

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Frequently asked questions

Your questions about Thiamin (Vitamin B1) and quality.

Thiamin plays a direct role in the conversion of carbohydrates into usable cellular energy. Specifically, thiamin pyrophosphate (TPP) is a coenzyme for pyruvate dehydrogenase — the enzyme complex that converts pyruvate (produced from carbohydrate breakdown) into acetyl-CoA, which then enters the citric acid cycle to produce ATP. Without adequate thiamin, this critical step in energy production is impaired. This is why EFSA recognises that thiamin contributes to normal energy-yielding metabolism.
The EU Nutrient Reference Value (NRV) for thiamin (vitamin B1) is 1.1 mg per day. Our Vitamin B Complex provides exactly 1.1 mg of thiamin hydrochloride per serving — 100% NRV. Thiamin requirements can increase with higher carbohydrate consumption, alcohol intake, and during pregnancy and breastfeeding. As a water-soluble vitamin, thiamin is not stored in large amounts — the body holds only about 30 mg total, lasting approximately 14–20 days without intake.
Thiamin is found in a wide variety of foods, though often in modest amounts. The richest sources include whole grains and fortified cereals, pork, fish (particularly trout and tuna), legumes (beans, lentils), seeds (sunflower seeds), nuts (macadamia, pecans), and yeast extracts. However, thiamin is sensitive to heat and can be lost during cooking (up to 50% loss). Additionally, some food processing methods like the milling of white rice and white flour remove thiamin-rich components. This is why many countries mandate the enrichment of refined flour products with thiamin.
Yes — alcohol consumption can significantly affect thiamin status. Alcohol impairs thiamin absorption in the gut, reduces thiamin storage in the liver, and increases thiamin excretion through urine. Additionally, people who consume alcohol regularly may have diets lower in thiamin-rich foods. Even moderate regular alcohol consumption can impact thiamin status over time. This is one reason why B-complex supplementation is commonly recommended for those who regularly consume alcohol. Our B Complex provides 100% NRV of thiamin to help maintain adequate levels.

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Thiamin B1 — fuelling your heart, nerves, and daily energy.

manufactured in Germany by an FSSC 22000 certified producer. Plant-based HPMC capsules. Free shipping from €49 across the EU.

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Ingredient Thiamin

Vitamin B1 — the energy-releasing vitamin for heart and nerve function.

What is Thiamin?

EFSA-approved health benefits

Why we use Thiamin in Nutri-Leaf formulas

Products containing Thiamin

Thiamin — the original B vitamin, essential for energy and nerves.

Benefits & research

Supplements containing Thiamin (Vitamin B1).

Vitamin B Complex

Guides about ingredients and nutrition.

Zinc and Selenium: The Dynamic Duo for Immune Health

How to Read a Supplement Label Like a Nutritionist

The Beginner’s Guide to Building a Daily Supplement Routine

Your questions about Thiamin (Vitamin B1) and quality.

Thiamin B1 — fuelling your heart, nerves, and daily energy.

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