Vitamin B1: how it works, signs of deficiency, and food sources
Vitamin B1 may not be the best-known vitamin, but it is one of the most fundamental. Four health claims have been officially approved for this vitamin, also known as thiamine. You’ll find them later in this article. The body cannot produce enough vitamin B1 on its own and stores very little of it. That’s why regular intake through food is important.
Many people search for vitamin B1 because they want to know which foods contain it, how to recognize a deficiency and whether you can also get too much vitamin B1. In this article, we explain what vitamin B1 does, which signs may indicate a vitamin B1 deficiency and when it is wise to pay extra attention.
What is vitamin B1?
Vitamin B1 is a water-soluble vitamin from the B-complex. Its official name is thiamine. Water-soluble means that the body does not store this vitamin in large amounts for long periods. Most of what is not used leaves the body through the urine.
Thiamine contributes to normal energy-yielding metabolism**. This means it is involved in converting carbohydrates from food into usable energy.
You can therefore think of vitamin B1 as a link in your daily energy metabolism.
A brief history: beriberi and thiamine
The history of vitamin B1 is linked to beriberi, a deficiency disease observed in the past in regions where polished white rice was the main part of the diet. Polishing rice removes the outer layer, which is precisely where thiamine is found.
The Dutch physician Christiaan Eijkman played an important role in early research into this connection. He observed that diet had a direct effect on the health of test animals. It was later scientifically established that this was related to thiamine, or vitamin B1.
Although severe deficiencies are uncommon in the Netherlands, inadequate vitamin B1 status can still occur in specific groups. This includes people with impaired absorption due to alcohol use, an unbalanced diet or increased physical needs.
What does vitamin B1 do?
These four health claims have been approved for vitamin B1 (thiamine):
- Thiamine contributes to normal energy-yielding metabolism**
- Thiamine contributes to the normal function of the nervous system**
- Thiamine contributes to normal psychological function**
- Thiamine contributes to the normal function of the heart**
When your intake is too low for a prolonged period, your thiamine status may decline. Further down, you can read about the signs that may be associated with this.
What foods contain vitamin B1?
The question of where to get vitamin B1 is relevant to anyone who wants to ensure their daily intake through food. Fortunately, vitamin B1 is found in many common foods.
Good sources of vitamin B1 include:
- Whole-grain products
- Oatmeal
- Brown rice
- Legumes
- Pork
- Nuts and seeds
- Potatoes
- Vegetables
- Yeast and fortified products
Whole-grain products usually contain more vitamin B1 than refined varieties. This is because B1 is found mainly in the germ and bran of grains. When grains are heavily processed, some of the vitamin is lost.
A practical example: choose whole-grain bread, oatmeal, or legumes more often instead of white rice or white bread. This way, you’ll get not only more vitamin B1 but also more fiber and minerals.
Would you like to learn more about other B vitamins? Then also read the article about vitamin B2. You’ll find biotin (vitamin B8) in our vitamins and minerals. Biotin is also in our supplements for energy and vitality, with the exact claim for each product.
Vitamin B1 deficiency symptoms and signs
Signs of low thiamine status can be subtle at first. This can sometimes make it difficult to recognize an inadequate intake right away. Early symptoms may resemble general feelings of fatigue.
Possible vitamin B1 deficiency symptoms and signs include:
- Feelings of fatigue
- Changes in appetite
- Irritability
- Effects on concentration and memory
- Muscle weakness
- Tingling in the limbs
- Effects on heart rate and breathing during exercise
- Fluid balance being out of balance
- Challenges with coordination
In the case of a prolonged and severe deficiency, the nerves and heart can be affected. This is especially seen in at-risk groups, such as people who drink excessively over a long period.
Situations like these should always be discussed with a doctor. So don’t experiment on your own if you have clear symptoms.
Who is more likely to have a vitamin B1 deficiency?
Low vitamin B1 status usually results from a combination of factors, such as low intake, reduced absorption in the intestines, or increased bodily needs.
Extra attention to intake is advisable for:
- People who regularly drink large amounts of alcohol
- Cases of severe malnutrition
- A very limited diet
- Digestive or absorption problems
- Recovery after bariatric surgery
- Pregnancy and breastfeeding
- Older adults with a limited diet
- Use of specific medication that affects excretion
Alcohol is a known risk factor because it can interfere with the body's absorption and processing of thiamine.
Symptoms of excessive vitamin B1: is there a risk?
People often search for symptoms of excessive vitamin B1. Because vitamin B1 is water-soluble, excess is usually eliminated naturally by the body. The Dutch Health Council has therefore not established a specific tolerable upper intake level for this vitamin.
However, this does not mean that an extremely high dosage is always beneficial. With a varied diet, extra supplementation is not always necessary. Although side effects are rare at common dosages, some people may be sensitive to supplements and experience mild stomach or skin reactions.
The basic principle is that more is not always better. Use a supplement for a specific purpose, for example, when your needs are higher or on the advice of a professional. For more information about dosages, also read the article about too much vitamin B6.
Do you need a vitamin B1 supplement?
Most people can get enough vitamin B1 from their daily diet. A supplement is therefore not generally necessary. However, a vitamin B1 supplement may be beneficial for specific at-risk groups or when recommended by a specialist based on a blood test or dietary analysis.
When choosing supplements, consider:
- The dosage per unit
- How it fits into your current diet
- Combining with other supplements or a multivitamin
- Potential interactions with medication
- Expert advice if in doubt
If you are unsure about your vitamin status, it is wiser to get tested and seek advice than to take high doses on your own.
Conclusion
Vitamin B1, or thiamine, has four approved health claims. Thiamine contributes to normal energy-yielding metabolism**. Thiamine contributes to the normal function of the nervous system**. Thiamine contributes to normal psychological function**. Thiamine contributes to the normal function of the heart**. Because the body stores very little thiamine, obtaining it from food every day is essential.
Good sources include whole-grain products, legumes, and nuts. Although deficiency is uncommon in the general population, there are specific groups for whom extra attention to vitamin B1 status is advisable. The first signs of low intake are often nonspecific, while prolonged deficiencies can have more serious consequences.
A healthy lifestyle with a varied diet is the foundation. If you have symptoms or questions about your personal needs, consulting a doctor or dietitian is the right step.
FAQ
What is vitamin B1?
Vitamin B1 is another name for thiamine, a water-soluble B vitamin. Thiamine contributes to normal energy-yielding metabolism**.
What foods contain vitamin B1?
Important sources of vitamin B1 include whole-grain products, oatmeal, legumes, potatoes, and nuts.
What are the signs of a vitamin B1 deficiency?
Possible signs include fatigue, irritability, reduced appetite, and effects on concentration or muscle strength.
Can you get too much vitamin B1?
Because the vitamin is water-soluble, the likelihood of symptoms from too much vitamin B1 is very low at normal intake, as excess is excreted in urine.
References
Disclaimer: This article is for informational purposes only. Nutritional information is not a substitute for medical advice. If you have health problems or concerns about your health, always consult a qualified professional.
**Approved health claim (Regulation (EU) No 432/2012)
