Vitamin B1, also known as thiamin , is a water-soluble vitamin that plays a key role in energy metabolism and nervous system function. It is one of the eight B vitamins and is responsible for converting carbohydrates into energy, which the body needs for everyday functions. Thiamin is essential for nerve and muscle health and supports the cardiovascular system. In this article, you'll learn why vitamin B1 is important, its health benefits, and how to use it safely.

What is vitamin B1 (thiamine)?

Vitamin B1 is a water-soluble vitamin that the body cannot store on its own, so it must be regularly supplied through food or supplements. Thiamine is crucial for carbohydrate metabolism because it is involved in the production of ATP (adenosine triphosphate), the main energy source for cells. It also plays an important role in the functioning of the nervous system by supporting communication between nerves and muscles [1].

Synonyms for vitamin B1

In addition to the name vitamin B1, thiamine is also known as aneurin or thiamine hydrochloride . In dietary supplements and foods, it is often listed as thiamine mononitrate or thiamine hydrochloride . These terms refer to the same bioactive form of vitamin B1 [2].

Where does vitamin B1 come from?

Vitamin B1 is found in many plant and animal foods, including whole grain products, meat, fish, and legumes. Pork, sunflower seeds, and legumes such as lentils and beans are particularly rich in thiamine. Because thiamine is water-soluble and the body can only store small amounts, regular dietary intake is necessary [3].

How is vitamin B1 produced?

Vitamin B1 is both naturally obtained from foods and synthetically produced. In dietary supplements, it is often used in stable forms such as thiamine mononitrate or thiamine hydrochloride, which are easily absorbed by the body. It is available in various dosage forms, including capsules, tablets, and powder [4].

Health benefits of vitamin B1

Vitamin B1 and energy metabolism

One of the most important benefits of vitamin B1 is its role in energy metabolism. It helps the body convert carbohydrates into energy by acting as a coenzyme for enzymes that regulate glucose metabolism. Thiamine contributes to the production of ATP, which is necessary for energy production in all body cells. People with low thiamine levels may experience fatigue, muscle weakness, and reduced physical performance [5].

Vitamin B1 and nerve function

Thiamine plays a key role in the nervous system, as it is required for the transmission of nerve impulses between the brain and muscles. It supports the synthesis of acetylcholine, a neurotransmitter important for muscle contraction and nerve communication. A deficiency in thiamine can lead to neurological disorders such as numbness, tingling in the extremities, or even more serious conditions such as Wernicke-Korsakoff disease , a form of brain damage commonly found in alcoholics [6].

Vitamin B1 and heart health

Vitamin B1 plays an important role in heart health, supporting the proper function of the heart muscle. A deficiency in thiamine can lead to heart problems such as heart failure, as the heart cannot function properly without adequate energy. Studies have shown that vitamin B1 supplementation can help relieve the symptoms of heart failure and improve heart function, especially in people with chronic heart problems [7].

Vitamin B1 and mood

Vitamin B1 may also influence mood and emotional well-being by supporting neurotransmitter regulation in the brain. Thiamine deficiency has been linked to increased irritability, depression, and memory problems. Adequate thiamine intake may help improve cognitive function and stabilize mood, especially in people with low thiamine levels [8].

Vitamin B1 and immune function

Thiamine also contributes to immune system support, as it is involved in supplying energy to immune cells. Adequate thiamine levels help strengthen the immune system by improving immune cell function and reducing inflammatory responses in the body. People with thiamine deficiency may have a weakened immune system and be more susceptible to infections [9].

How does vitamin B1 work in the body?

Vitamin B1 acts as a coenzyme in various biochemical reactions related to carbohydrate metabolism and energy production. It is particularly important for the conversion of pyruvate, a waste product of glucose metabolism, into acetyl-CoA, which enters the citric acid cycle to produce energy in the form of ATP. Thiamine also supports neurotransmitter activity and contributes to the proper functioning of the nervous system by facilitating the transmission of nerve impulses [10].

Recommended dosage and use of vitamin B1

What is the recommended dosage?

The recommended daily intake (RDA) of vitamin B1 depends on age and gender. Adult men need about 1.2 mg of thiamine per day, while women need about 1.1 mg. Pregnant and breastfeeding women have slightly higher needs. When taking supplements to treat thiamine deficiency or certain medical conditions, higher doses may be required, typically between 50 and 300 mg per day, depending on a physician's recommendation [11].

When should you take vitamin B1?

Vitamin B1 can be taken at any time of day, ideally with a meal to improve absorption. Because thiamine is water-soluble, excess vitamin is easily excreted in the urine, so daily intake is necessary to meet requirements. People with increased needs, such as athletes or those with metabolic disorders, may want to consider supplementation [12].

Side effects and safety of vitamin B1

Is vitamin B1 safe?

Vitamin B1 is considered very safe and well-tolerated because it is water-soluble and excess thiamine is easily excreted. No serious side effects have been reported, even at high doses. At very high doses, which are rarely used in therapeutic scenarios, gastrointestinal disturbances may occur, but these are usually mild [13].

What are the side effects of vitamin B1?

Rare side effects of vitamin B1 include gastrointestinal disturbances such as nausea or stomach cramps, especially at higher doses. In very rare cases, allergic reactions may occur, especially in people sensitive to B vitamin complexes. It is recommended to always take vitamin B1 according to the instructions and consult a doctor if you are unsure [14].

Vitamin B1 compared to other B vitamins

Vitamin B1 vs. Vitamin B12

Both vitamin B1 and vitamin B12 are important for energy metabolism and nerve function, but they have different roles. While vitamin B1 is primarily responsible for the conversion of carbohydrates into energy and nerve impulse transmission, vitamin B12 plays a key role in red blood cell production and DNA synthesis. Both vitamins are important for the nervous system and general energy metabolism, but they act through different pathways [15].

Vitamin B1 vs. Vitamin B6

Vitamin B1 and vitamin B6 are both essential B vitamins, but they have different functions in the body. While vitamin B1 primarily supports carbohydrate metabolism and nerve function, vitamin B6 is responsible for protein metabolism and the production of neurotransmitters such as serotonin and dopamine. Both vitamins are important for the well-being and health of the nervous system and should be obtained in sufficient quantities through diet or supplements [16].

Natural sources of vitamin B1

Vitamin B1 is found in many foods, especially whole grain products, pork, fish, beans, and nuts. Whole-grain bread, oatmeal, sunflower seeds, and pork liver are particularly rich in thiamine. Because thiamine is sensitive to heat and water, long cooking times or boiling in water can reduce the thiamine content of foods, making it important to choose a varied diet [17].

Final thoughts on vitamin B1

Vitamin B1 (thiamine) is an essential vitamin that offers numerous health benefits, including supporting energy metabolism, nerve function, and heart health. It is easily absorbed through food or supplements and plays a crucial role in overall health and well-being. For people looking to boost their energy, support their nerve health, or improve their mood, vitamin B1 is a valuable supplement.