Vitamin B1
Synonym(s): B vitamins, thiamine, thiamine mononitrate
Nutrient group: Vitamine
Sources and physiological effects
| Dietary sources |
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Vitamin B1 is a water-soluble vitamin, which is almost ubiquitous in the diet, but usually only present in low concentrations. Considerable amounts of vitamin B1 are found in the germ and in the outer layers of whole grains. However, a high percentage of vitamin B1 is lost in milling processes. Other notable vegetable sources of vitamin B1 include potatoes, legumes and nuts. Pork and offal are considered good sources of animal vitamin B1. Here vitamin B1 does not occur in free form, but as biologically active thiamine diphosphate (also: thiamine pyrophosphate). Certain fruits (e.g. cherries, blackberries, apples) contain antithiamine factors that reduce the bioavailability of vitamin B1. Phenolic substances (e.g. coffee, choloric acid, tannins) and the enzyme thiaminase (sources: raw fish, some bacteria/plants) also act as antithiamine factors. In practice, however, these disruptive factors have no significance in normal nutrition. However alcohol interferes with the absorption and utilization of the vitamin and chronic abuse can lead to a deficiency. During food preparation, variable and sometimes significant vitamin B1 losses occur. The reason for this is the sensitivity of the vitamin to heat, water solubility and oxidation. On average, around 30% of vitamin B1 is destroyed during meal preparation. When cooking vegetables losses can be as high as 60 %. Soaking, peeling and the addition of sulfites to food preservatives also lead to thiamine losses.
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| Physiological effects |
| Nervous system |
- Influences the neurotransmitters GABA and serotonin
- Antagonist of acetylcholine, one of the most important neurotransmitters in the central and peripheral nervous systems
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| Energy metabolism |
- As coenzyme involved in the production of energy from food
- Introduction of carbohydrates into the citrate cycle (cofactor of pyruvate dehydrogenase)
- Provision of NADPH for nucleotide biosynthesis (vitamin B1-dependent transketolase)
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| Heart function |
- As cofactor of energy metabolism involved in supporting cardiac function
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EFSA Health Claims
| Health claims |
EFSA opinion |
| Vitamin B1 (Thiamine) |
- Contributes to normal mental function
- Contributes to a normal energy metabolism
- Contributes to normal functioning of the nervous system
- Contributes to normal heart function
|
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Recommended intake
D-A-CH recommended nutrient intake (Reference values EFSA and NHI   ) |
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Age |
Vitamin B1 (mg/d) |
| Infants (months) |
| |
0-4 |
0.2 |
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4-12 |
0.4 |
| Children (years) |
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1-4 |
0.6 |
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4-7 |
0.8
|
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7-10 |
1.0 |
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10-13 |
1.1 |
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13-15 |
1.25 |
| Teenagers/adults (years) |
Women |
Men |
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15-19 |
1.1 |
1.4 |
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19-25 |
1.0 |
1.3 |
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25-51 |
1.0 |
1.2 |
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51-65 |
1.0 |
1.2 |
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> 65 |
1.0 |
1.1 |
| Pregnancy |
2nd trimester 1.2
3rd trimester 1.3
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| Breast-feeding |
1.3 |
| Increased need |
Age, pregnancy, fever, stress, sport, unblanaced and carbohydrate-rich nutrition, high coffee/tea consumption, alcohol abuse, diseases such as diabetes mellitus, depression, alzheimer's disease, pain conditions |
| Special groups at risk of deficiency |
Diabetes mellitus, alcoholics |
| Recommended intakes according to food labelling regulations |
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| (=100 % TB marking on label) |
1.1 mg |
| Safety of the nutrient |
|
UL
|
Long-term daily intake, where no
adverse health effects are expected |
k. A. |
NOAEL
|
Maximum intake, with no observed
adverse effect |
k. A. |
Detailed information
| Absorption of vitamin B1 |
Vitamin B1 is taken up in the intestine via the thiamine transporters 1 and 2. With the aid of the enzyme thiamine pyrophosphokinase, it is first converted into thiamine pyrophosphate (TPP, also known as thiamine diphosphate, TDP). In this biologically active form it acts as a coenzyme of pyruvate dehydrogenase E1, α ketoglutarate dehydrogenase and transketolase.
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| Key role in cellular energy metabolism |
Vitamin B1, like all B vitamins, plays a key role in the citrate cycle. It helps in the decarboxylation of pyruvate to acetyl-CoA and is involved in the conversion of ribose-5-phosphate to fructose-6-phosphate. In addition, the pentose phosphate cycle is catalyzed by a vitamin B1-dependent enzyme. Vitamin B1-deficiency can lead to Beriberi disease due to its central role in energy metabolism. Classic beriberi symptoms include fatigue, lethargy, disorders of the heart, circulation, nerves and muscles.
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| Vitamin B1 and microangiopathies |
Vitamin B1 plays an important role in maintaining endothelial vascular function and lipid profile and in the development of retinopathies, nephropathies, cardiopathies and neuropathies. Micro- and macroangiopathies occur primarily as late sequelae of diabetes mellitus disease or are alcohol-related (1).
Supportive therapeutic intervention with high doses of B vitamins can have a positive effect on pain in polyangiopathies and improve the symptoms of diabetic neuropathies (2). Among other actions, this seems to occur via a direct protective effect of vitamin B1 on glucose-induced changes in the cell membranes (3). Vitamin B1 was able to reverse endothelial damage caused by high glucose levels in cellular experiments (4). |
| B vitamins and neurological significance |
| In addition to energy production, vitamin B1 is important for the structure and functioning of nerve cells. An undersupply is expressed accordingly through non-specific neurological symptoms such as nervousness or lack of concentration (5). Changes in the behavior of children and adolescents are also possible. A targeted improvement of deficiency through supplementation enables a fundamental improvement of neurological symptoms. |
Reference values
| Parameter |
Substrate |
Reference value |
Description |
| Thiamine |
Whole blood |
29 - 52 µg/l |
Fasted (12 hours fasting). Transport: protected from light. |
| Transketolase activity test |
Red cell hemolysate |
>1,25
Limit value
1,20-1,25 |
Vitamin B1 is cofactor of erythrocytic transketolase. A decreased transketolase activity in the erythrocytes indicates vitamin B1 deficiency. An increase in transketolase activity in the erythrocytes after addition of thiamine pyrophosphate (TPP effect) is a good indicator of vitamin B1 deficiency. If activity increases by more than 15%, a deficiency is likely. |
| Interpretation |
| Decreased values |
Vitamin B1-deficiency, decrease of vitamin supply in the body and decrease of vitamin B1-dependent enzyme activity |
| Increased values |
Overdose of vitamin B1 or vitamin B complex preparations |
Deficiency symptoms
| Impact on |
Symptoms |
| General health |
Weight loss, loss of appetite, irritability, insomnia |
| Nerve system |
Peripheral neuropathies, weakness, fatigue, burning feet |
| Blood count |
Anemia, thrombocytopenia |
| Cardiovascular system |
Heart failure, tachycardia, edema (beriberi) |
| Sequelae of diabetes |
Polyneuropathies, Angiopathies |
| Alcohol abuse sequelae |
Wernicke encephalopathy (paresis of eye muscles, ataxia, psychoses, cerebellar atrophy), polyneuropathies |
Indications
| Effect |
Indication |
Dosage |
Physiological effects
at a low intake |
Therapeutic support for diabetes mellitus and diabetic polyneuropathy |
50 - 100 mg/d |
| Therapeutic support in alcoholic polyneuropathy |
150 - 500 mg/d |
| Adjuvant for long-term use of antacids, antidepressants, diuretics and alcohol abuse |
10 - 50 mg/d |
Pharmacological effects
at a high intake |
Therapeutic support for herniated disc, carpal tunnel syndrome or restless legs syndrome or hand-foot syndrome |
300 - 600 mg/d |
Administration
| General mode of administration |
When
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B vitamins can be ingested between or with meals. |
| Side effects |
| Very rare after long-term high dosage (50 mg/kg or >3000 mg/d) headache, sweating, tachycardia, itching or urticaria may occur. |
| Contraindications |
| Suspected hypersensitivity to vitamin B1 |
Interactions
| Drug interactions |
| Antiepileptics (e.g. phenytoin) |
Increase in vitamin B1-demand due to increased vitamin B1-degrading due to enzyme induction caused by antiepileptic drugs |
| Loop diuretics (e.g. furosemide) |
Increased renal vitamin B1 excretion
Furosemide affects vitamin B1 uptake in cardiocytes
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| Oral contraceptives |
Disorders of vitamin B1 absorption and utilization |
| Nutrient interactions |
| Trace elements |
Magnesium deficiency leads to inhibition of phosphorylation of thiamine to thiamine diphosphate. |
| Vitamins |
Vitamin B1 works synergistically with all B vitamins, especially vitamin B2 and B3 |
Description and related substances
| Description of the micronutrient |
| Water soluble vitamin of the B complex |
| Related substances |
| Thiamine hydrochloride, thiamine mononitrate, thiamine monophosphate chloride, thiamine pyrophosphate chloride
Notes:
Benfotiamine is a fat-soluble compound that is used in therapy. This compound is only approved in medications. As stated by Uwe Gröber.
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References
| References |
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1 ) Al-Daghri, N. M. et al. 2015. Biochemical changes correlated with blood thiamine and its phosphate esters levels in patients with diabetes type 1 (DMT1). International Journal of Clinical and Experimental Pathology. 8(10):13483-13488.
2) Haupt, E. et al. 2005. Benfotiamin (vitamin B1) in the treatment of diabetic polyneuropathy - a three-week randomized, controlled pilot study. Int J Clin Pharmacol Ther. 43(2):71-7.
3) Beltramo, E. et al. 2004. Thiamin and benfotiamine prevent increased apoptosis in endothelial cells and pericytes cultured in high glucose. Diabetes Metab Res Rev. 20(4):330-6.
4) Beltramo E. et al. 2009. Thiamine and benfotiamine prevent apoptosis induced by high glucose-conditioned extracellular matrix in human retinal pericytes. Diabetes Metab Res Rev. 25(7):647-56. doi: 10.1002/dmrr.1008.
5) Universität Wien. Österreichischer Ernährungsbericht. Wien: Bundesministerium für Gesundheit, 2008.
References Interactions
Stargrove, M. B. et al. Herb, Nutrient and Drug Interactions: Clinical Implications and Therapeutic Strategies, 1. Auflage. St. Louis, Missouri: Elsevier Health Sciences, 2008.
Gröber, U. Mikronährstoffe: Metabolic Tuning –Prävention –Therapie, 3. Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2011.
Gröber, U. Arzneimittel und Mikronährstoffe: Medikationsorientierte Supplementierung, 3. aktualisierte und erweiterte Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2014.
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