Vitamin B1: benefits, dosage, contraindications
Other name(s)
Thiamine, aneurine
Scientific name(s)
Thiamine
Family or group:
Vitamins
Indications
Scoring methodology
EFSA approval.
Vitamin B1 deficiency ✪✪✪✪✪
Today, vitamin B1 is mainly used to treat insufficient intake (in people who eat primarily white rice) and deficiencies. Thiamine deficiency can occur in cases of alcoholism (due to poor dietary intake), during an 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 consuming high amounts of carbohydrates, such as athletes. Thiamine deficiency manifests as a disease called beriberi, which presents with a wide range of symptoms such as foot pain, difficulty moving, heart failure, decreased intellectual capacity, psychosis, etc. The usual dose of thiamine is 5 to 30 mg per day, given as a single dose or in divided doses for one month. The dose can be increased up to 300 mg per day in cases of severe deficiency.
Posologie
Oral
5 - 30 mg
Acid-Base Balance ✪✪✪✪✪
Thiamine pyrophosphate (or thiamine diphosphate, TPP) is involved in carbohydrate metabolism and the generation of energy stores, in the breakdown of pyruvate whose accumulation leads to an overproduction of lactates. The accumulation of lactates results in excessive production of lactic acid and lactic acidosis (defined by acidosis associated with hyperlactatemia).
Posologie
Oral
1.1 mg
Cataract ✪✪✪✪✪
Studies have shown that a high dietary intake of thiamine was associated with a 40% reduction in the risk of developing cataract.nn
Posologie
Orally
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.nn
Posologie
Orally
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 an overall improved mood: a clear mind, calmness, and increased energy. nnResearch indicates that thiamine, when added to standard treatment (fluoxetine), can improve depressive disorders more significantly compared with taking fluoxetine with a placebo.nnIt should be noted that thiamine acts as a cofactor in several important metabolic reactions, particularly in neurotransmission.nn
Posologie
Orally
50 mg
Cognitive performance ✪✪✪✪✪
Thiamine is essential for the normal functioning of the nervous system and for normal intellectual abilities. However, supplementation is not associated with an improvement in memory. Based on average dietary thiamine intake, studies have reported a significant association between thiamine consumption and better cognitive function, particularly in abstract reasoning; however, there was no significant association between thiamine consumption and visuospatial abilities or nonverbal 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 albumin excretion in the urine in patients with type 2 diabetes compared with placebo
Posologie
Oral
300 mg
3 months
Cardiac disorders ✪✪✪✪✪
Population studies indicate that adults with heart failure are at increased risk of thiamine deficiency compared with the general population, with thiamine deficiency rates ranging from 3% to 91%. Preliminary clinical research shows that thiamine supplementation may slightly improve left ventricular ejection fraction in adults with systolic heart failure, although some studies show no improvement. nnIt should be noted, however, that thiamine is essential for normal heart function.nn
Posologie
Oral
200 - 300 mg
6 - weeks
Type 2 diabetes ✪✪✪✪✪
Preliminary clinical research shows that taking 100 mg of thiamine orally three times daily for 6 weeks slightly reduces 2-hour postprandial plasma glucose levels compared with baseline in patients with glucose intolerance (prediabetes stage).nn
Posologie
Oral
300 mg
Adults
Depression ✪✪✪✪✪
Preliminary clinical research in adults with major depressive disorder shows that taking thiamine at 300 mg per day, in combination with 20 mg of fluoxetine per day, leads to greater improvement in depressive symptoms after 6 weeks compared with fluoxetine combined with placebo. This suggests that thiamine may accelerate symptom improvement when initiating 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, thiamine deficiency occurs due to reduced intake, impaired absorption, and decreased thiamine storage. 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 stored only in very small amounts in the muscles, the nervous system and the liver. In the absence of sufficient external intake, these stores are depleted within 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 the production of energy reserves, in the breakdown of pyruvate whose accumulation leads to an overproduction of lactate (toxic to all cells, but particularly to neurons and glial cells). TPP also participates in the oxidative decarboxylation of pyruvate, which is a necessary step for the formation of acetylcholine (a neurotransmitter). - Thiamine triphosphate, whose role is still poorly understood, is thought to be involved in cell signaling processes and neurotransmission. A deficiency in TPP or its cofactors (such as magnesium) therefore leads to cellular distress (energy failure), particularly for the nervous system and the cardiac muscle (the tissues with the highest energy demand).
Usages associés
Neurological
Thiamine pyrophosphate (or thiamine diphosphate, TPP) is involved in the breakdown of pyruvate, the accumulation of which leads to an overproduction of lactate (toxic to all cells, but particularly to neurons and glial cells). TPP is also involved in the oxidative decarboxylation of pyruvate, which is a necessary step in the formation of acetylcholine (a neurotransmitter). Thiamine may also be involved in neuromuscular transmission. The pathological consequences of thiamine deficiency and disorders of thiamine metabolism are divided into three syndromes: - Beriberi: a syndrome that, to varying degrees, combines a sensorimotor polyneuropathy and a (sub)acute dilated cardiomyopathy. - Wernicke encephalopathy (or Wernicke syndrome, or Gayet-Wernicke): a relatively common syndrome variably characterized by confusion, oculomotor disturbances, and balance disorders. - Korsakoff syndrome: produces a characteristic and generally irreversible pseudo-dementia. It usually occurs as a late complication of Wernicke 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 needed for optimal neuronal function and nerve transmission. Thiamine is also involved in the synthesis of acetylcholine, a neurotransmitter important for memory and learning. A deficiency in vitamin B1 can therefore affect cognition by reducing the energy available for brain activities and by disrupting neuronal communication.
Usages associés
Cardiovascular
Some studies show that vitamin B (thiamine) may improve vasodilation in healthy subjects, diabetic subjects, and those with prediabetes. Thus it may help prevent cardiovascular complications. Other clinical research has shown that thiamine may cause a slight decrease in diastolic blood pressure compared with baseline values in patients with hyperglycemia who have normal blood pressure readings.
Usages associés
Nephroprotective
Animal research suggests that thiamine deficiency in people with diabetes may exacerbate the development of diabetic nephropathy. In diabetic nephropathy, it is thought that dysfunction of glomerular endothelial cells, podocytes (epithelial cells in the renal glomerulus), and tubular epithelial cells can be improved by increasing plasma thiamine concentration. This is achieved by improving glomerular and tubular structure and function as well as reducing vascular inflammation, thereby decreasing albumin excretion in the urine.
Usages associés
Safe dosage
Adult aged 74 years and older: 1.2 mg
Adolescent aged 13 to 19 years: 1.3 mg
Oral thiamine has no known toxicity at the doses usually used. When administered intravenously, anaphylactic reactions have been reported only rarely. At high doses or in patients at risk, it may affect glucose balance.
Pregnant women aged 18 years and older: 1.8 mg
Consumption of thiamine at recommended doses poses no risk during pregnancy. Furthermore, there is insufficient reliable information on the safety of using high doses of vitamin B1 during pregnancy.
Child from 1 to 3 years: 0.4 mg
Lactating woman 18 years and older: 1.8 mg
Consumption of thiamine at recommended doses poses no risk during breastfeeding. Furthermore, there is insufficient reliable information on the safety of using high doses of vitamin B1 during breastfeeding.
Infant up to 12 months: 0.2 mg
Female aged 13 to 19 years: 1.1 mg
Oral thiamine has no known toxicity at commonly used doses. When given intravenously, anaphylactic reactions have been reported only rarely. At high doses or in patients at risk, it can disrupt glucose 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 aged 19 to 74 years: 1.3 mg
Woman aged 19 to 74 years: 1.1 mg
Interactions
Médicaments
Oral contraceptives: minor interaction
Some studies have reported a slight reduction in transketolase activity (an enzyme that depends on thiamine) in women taking oral contraceptives, suggesting a mild thiamine deficiency. However, other studies found no effect. Routine use of thiamine supplements with oral contraceptives is not necessary.
Diuretics: moderate interaction
An increase in urinary excretion of thiamine can cause a deficiency in some people treated with diuretics, particularly when high doses are used for several months. Most cases involve elderly people whose dietary vitamin intake may be insufficient.
Fluorouracil: moderate interaction
People receiving chemotherapy regimens containing fluorouracil may be at risk of thiamine deficiency. Fluorouracil can interfere with activation of the vitamin or increase its breakdown. However, there is not enough research to recommend routine supplementation.
Metformin: moderate interaction
Metformin (an antidiabetic) may reduce thiamine activity, which can result in increased conversion of pyruvate to lactic acid. Accumulation of lactic acid can lead to lactic acidosis.
Phenytoin: moderate interaction
Some evidence suggests that chronic phenytoin therapy may reduce thiamine levels in plasma and cerebrospinal fluid, as well as its uptake into nervous tissue. Theoretically, this could contribute to phenytoin's side effects, such as polyneuropathy and cerebellar ataxia. However, it is unclear whether affected patients also have other factors contributing to thiamine deficiency, such as poor dietary intake. Due to lack of evidence, routine thiamine supplementation is still not recommended in 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.
