Vitamin B1: benefits, dosage, contraindications
Other name(s)
Thiamine, aneurine
Scientific name(s)
Thiamine
Family or group:
Vitamins
Indications
Rating methodology
EFSA approval.
Vitamin B1 Deficiency ✪✪✪✪✪
Today, vitamin B1 is primarily used to treat insufficiencies (in people who mainly consume white rice) and deficiencies. Thiamine deficiency can occur in case of alcoholism (due to lack of food intake), acute infection or chronic intestinal diseases, in people who have undergone stomach surgery that limits its absorption, as well as in people taking certain diuretics or ingesting high quantities of carbohydrates, like athletes for example. Thiamine deficiency results in a disease called beriberi, which manifests with a wide range of symptoms such as foot pain, difficulty moving, heart failure, diminished intellectual capacity, psychosis, etc. The typical dose of thiamine is 5 to 30 mg per day in a single dose or in divided doses over one month. The dose can be up to 300 mg per day in severe deficiency cases.
Posologie
Oral
5 - 30 mg
Acid-Base Balance ✪✪✪✪✪
Thiamine pyrophosphate (or thiamine diphosphate, TPP) is involved in carbohydrate metabolism and energy reserve production, in the breakdown of pyruvate whose accumulation leads to lactic acid overproduction. Lactate accumulation results in excess lactic acid production and a lactic acidosis (defined by acidosis associated with hyperlactatemia).
Posologie
Oral
1.1 mg
Cataract ✪✪✪✪✪
Studies have shown that a high dietary thiamine intake is associated with a 40% reduction in the risk of developing cataracts.
Posologie
Oral
10 mg
Dysmenorrhea ✪✪✪✪✪
Studies suggest that taking 100 mg of thiamine hydrochloride per day for 90 days relieves pain in 87% of women with dysmenorrhea.
Posologie
Oral
100 mg
90 - days
Women
The Effect of Micronutrients on Pain Management of Primary Dysmenorrhea: a Systematic Review and Meta-Analysis
The Effects of Fish Oil Capsules and Vitamin B1 Tablets on Duration and Severity of Dysmenorrhea in Students of High School in Urmia-Iran
Emotional Balance ✪✪✪✪✪
Thiamine supplementation is associated with better general mood: clear mind, calm, energetic. Research indicates that thiamine, when combined with the basic treatment (fluoxetine), can improve depressive disorders more significantly compared to taking fluoxetine with a placebo. It should be noted that thiamine acts as a cofactor in several important metabolic reactions, particularly in neurotransmission.
Posologie
Oral
50 mg
Cognitive Performance ✪✪✪✪✪
Thiamine is essential for the normal functioning of the nervous system and normal intellectual abilities. However, supplementation is not associated with memory improvement. Based on average dietary thiamine intake, studies have reported a significant association between thiamine consumption and better cognitive function, notably in abstract reasoning; however, there was no significant association between thiamine consumption and visuospatial abilities or non-verbal learning and memory.
Posologie
Oral
1.1 mg
Role of Dietary Protein and Thiamine Intakes on Cognitive Function in Healthy Older People: A Systematic Review
Thiamine Supplementation Mood and Cognitive Functioning
Diabetic Nephropathy ✪✪✪✪✪
Preliminary clinical studies show that taking 100 mg of thiamine three times a day for 3 months significantly reduces urinary albumin excretion in patients with type 2 diabetes compared to placebo.
Posologie
Oral
300 mg
3 - months
Cardiac Disorders ✪✪✪✪✪
Population research indicates that adults with heart failure have an increased risk of thiamine deficiency compared to the general population, with deficiency rates ranging from 3% to 91%. Preliminary clinical research shows thiamine supplementation may slightly improve left ventricular ejection fraction in adults with systolic heart failure, though some studies show no improvement. However, it's important to remember that thiamine is essential for normal heart function.
Posologie
Oral
200 - 300 mg
6 - weeks
Type 2 Diabetes ✪✪✪✪✪
Preliminary clinical research shows that taking 100 mg of thiamine orally three times a day for 6 weeks slightly decreases 2-hour postprandial plasma glucose levels compared to the baseline in patients with glucose intolerance (pre-diabetic stage).
Posologie
Oral
300 mg
Adults
Depression ✪✪✪✪✪
Preliminary clinical research in adults with major depressive disorder shows that taking 300 mg of thiamine daily, combined with 20 mg of fluoxetine daily, results in a greater improvement in depressive symptoms after 6 weeks compared to fluoxetine combined with a placebo. This suggests that thiamine may accelerate symptom improvement during the initiation of fluoxetine treatment. However, after 12 weeks, improvement rates were similar between those receiving thiamine and those receiving placebo.
Posologie
Oral
300 mg
12 - weeks
Alcoholism ✪✪✪✪✪
In alcoholism, a thiamine deficiency occurs due to reduced intake, impaired absorption, and decreased storage of thiamine. Ethanol also decreases thiamine phosphorylation, reducing its conversion to the active form.
Posologie
Oral
5 - 30 mg
Properties
Essential
The human body is unable to produce thiamine and depends on dietary intake. It is only stored in very small quantities by muscles, the nervous system, and the liver. In the absence of sufficient external intake, these reserves are depleted in 2 to 3 weeks. Thiamine is the precursor of two bioactive forms necessary for the proper functioning of several metabolic pathways: - Thiamine pyrophosphate (or thiamine diphosphate, TPP) is involved in carbohydrate metabolism and energy reserve production, in the breakdown of pyruvate whose accumulation leads to overproduction of lactates (toxic for all cells, especially for neurons and glial cells). TPP is also involved in the oxidative decarboxylation of pyruvate, a necessary step for acetylcholine formation (a neurotransmitter). - Thiamine triphosphate, whose role is still poorly understood, is thought to be involved in cellular signaling and neurotransmission processes. A deficiency in TPP or its cofactors (such as magnesium) leads to cellular distress (energy insufficiency), particularly for the nervous system and heart muscle (the tissues most demanding in energy).
Usages associés
Neurological
Thiamine pyrophosphate (or thiamine diphosphate, TPP) is involved in the breakdown of pyruvate whose accumulation leads to overproduction of lactates (toxic for all cells, particularly neurons and glial cells). TPP is also involved in the oxidative decarboxylation of pyruvate, a necessary step for acetylcholine formation (a neurotransmitter). Thiamine may also be involved in neuromuscular transmission. The pathological consequences of deficiencies and metabolic disorders of thiamine are divided into three syndromes: - Beriberi: a syndrome combining to varying degrees a sensorimotor polyneuropathy and an acute dilated cardiomyopathy. - Wernicke's encephalopathy (or Wernicke's syndrome, or Gayet-Wernicke): a relatively common syndrome combining, to varying degrees, confusion, oculomotor disturbances, and balance disorders. - Korsakoff syndrome: presents a characteristic pseudo-dementia tableau, generally irreversible. It usually occurs as a late complication of Wernicke's encephalopathy.
Usages associés
Cognitive Function
Vitamin B1, or thiamine, plays a crucial role in maintaining cognitive function by acting as an essential coenzyme in the brain's energy metabolism. It helps convert nutrients into energy, necessary for the optimal functioning of neurons and nerve transmission. Thiamine is also involved in the synthesis of acetylcholine, an important neurotransmitter for memory and learning. A deficiency in vitamin B1 can therefore affect cognition by reducing the energy available for brain activities and disrupting neuronal communication.
Usages associés
Cardiovascular
Some studies indicate that vitamin B (thiamine) may improve vasodilation in healthy subjects, diabetics, and those with prediabetes. Thus, it may prevent cardiovascular complications. Other clinical research has shown that thiamine may cause a slight reduction in diastolic blood pressure from baseline in patients with hyperglycemia with normal blood pressure values.
Usages associés
Nephroprotective
Animal research suggests that thiamine deficiency in diabetics may exacerbate the development of diabetic nephropathy. In diabetic nephropathy, endothelial cell dysfunction, podocyte (renal glomerulus epithelial cells) dysfunction, and tubular epithelial cell dysfunction are thought to be improved by increasing plasma thiamine concentration, through improved glomerular and tubular structure and function as well as vascular inflammation, thereby reducing albumin excretion in urine.
Usages associés
Safety dosage
Adult from 74 years: 1.2 mg
Adolescent from 13 to 19 years: 1.3 mg
Oral thiamine has no known toxicity at commonly used doses. Intravenous administration can exceptionally cause anaphylactic reactions. At high doses or in at-risk patients, it may disturb carbohydrate balance.
Pregnant woman from 18 years: 1.8 mg
Thiamine consumption at recommended doses poses no risk during pregnancy. However, there is no reliable and sufficient information on the safety of using high doses of vitamin B1 during pregnancy.
Child from 1 to 3 years: 0.4 mg
Breastfeeding woman from 18 years: 1.8 mg
Thiamine consumption at recommended doses poses no risk during breastfeeding. However, there is no reliable and sufficient information on the safety of using high doses of vitamin B1 during breastfeeding.
Infant up to 12 months: 0.2 mg
Woman from 13 to 19 years: 1.1 mg
Oral thiamine has no known toxicity at commonly used doses. Intravenous administration can exceptionally cause anaphylactic reactions. At high doses or in at-risk patients, it may disturb carbohydrate balance.
Child from 4 to 6 years: 0.6 mg
Child from 7 to 9 years: 0.8 mg
Child from 10 to 12 years: 1 mg
Man from 19 to 74 years: 1.3 mg
Woman from 19 to 74 years: 1.1 mg
Interactions
Médicaments
Oral contraceptives: low interaction
Some studies have reported a slight reduction in the activity of transketolase (an enzyme dependent on thiamine) in women taking oral contraceptives, suggesting a slight thiamine deficiency. However, other studies have shown no effect. Systematic use of thiamine supplements with oral contraceptives is not necessary.
Diuretics: moderate interaction
Increased urinary excretion of thiamine may lead to a deficiency in some individuals treated with diuretics, particularly at high doses for several months. Most cases concern elderly people whose vitamin intake in the diet may be insufficient.
Fluorouracil: moderate interaction
Individuals receiving chemotherapy treatments containing fluorouracil may be at risk of thiamine deficiency. Fluorouracil may interfere with the activation of the vitamin or increase its degradation. However, there is not enough research to recommend required supplementation.
Metformin: moderate interaction
Metformin (an antidiabetic drug) may reduce thiamine activity, which can lead to an increase in the quantities of pyruvates converted into lactic acid. Accumulation of lactic acid may lead to lactic acidosis.
Phenytoin: moderate interaction
Some evidence suggests that chronic treatment with phenytoin may reduce thiamine levels in the plasma and cerebrospinal fluid, as well as its absorption in nervous tissues. Theoretically, this may contribute to the side effects of phenytoin, such as polyneuropathy and cerebellar ataxia. However, it is unclear whether the affected patients also have other factors contributing to thiamine deficiency, such as dietary insufficiency. Due to a lack of evidence, systematic thiamine supplementation is not yet recommended for patients treated with phenytoin.
Plantes ou autres actifs
Vitamin B1: moderate interaction
Field horsetail contains a thiaminase-like compound that can destroy thiamine in the stomach and theoretically cause symptomatic deficiency. Avoid using this plant in people at risk of thiamine deficiency.
