Aneurine HCL, aneurine mononitrate, antiberiberi factor, antiberiberi vitamin, antineuritic factor, antineuritic vitamin, anurine, B complex vitamin, beta-hydroxy-ethylthiazolium chloride, thiamin chloride, thiamin diphosphate, thiamin HCL, thiamin hydrochloride, thiamin monophosphate (TMP), thiamin nitrate, thiamin, thiamin pyrophosphate (TPP), thiamin triphosphate (TTP), thiamine chloride, thiaminium chloride HCL, thiaminium chloride hydrochloride.

Combination products: Thiamin is frequently used in combination with other B vitamins in vitamin B complex formulations. Vitamin B complexes generally also include vitamin B2 (riboflavin), vitamin B3 (niacin/niacinamide), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B12 (cyanocobalamin), and folic acid. However, some products do not contain all of these vitamins, and may include others such as biotin, para-aminobenzoic acid (PABA), choline bitartrate, and inositol. Refer to the manufacturer's label for details.

Thiamin (also spelled "thiamine") is a water-soluble B-complex vitamin, previously known as vitamin B1 or aneurine. Thiamin was isolated and characterized in the 1920s, and thus was one of the first organic compounds to be recognized as a vitamin.

Thiamin is involved in numerous body functions, including: nervous system and muscle functioning; flow of electrolytes in and out of nerve and muscle cells (through ion channels); multiple enzyme processes (via the coenzyme thiamin pyrophosphate); carbohydrate metabolism; and production of hydrochloric acid (which is necessary for proper digestion). Because there is very little thiamin stored in the body, depletion can occur as quickly as within 14 days.

Thiamin deficiency (beriberi): Severe chronic thiamin deficiency can result in potentially serious complications involving the nervous system/brain, muscles, heart, and gastrointestinal system. Consequences of thiamin deficiency were described as early as 2600 B.C. in Chinese texts, and have been labeled historically with the term "beriberi." Beriberi has been divided into three subtypes: dry beriberi refers to neuromuscular complications such as peripheral neuropathy and weakness; wet beriberi refers to cardiovascular complications such as heart failure (Shoshin-type beriberi); and cerebral beriberi refers to central nervous system (brain) complications such as Wernicke's encephalopathy (abnormal eye movements, stance/gait abnormalities, mental dysfunction) or Korsakoff's psychosis (apathy, confusion, severe memory deficits/amnesia). Thiamin deficiency may result from inadequate thiamin intake, an increased requirement for thiamin, excessive loss of thiamin from the body, or consumption of anti-thiamin factors in food. People at particular risk for thiamin deficiency include chronic alcoholics, patients receiving intravenous feeding (total parenteral nutrition/TPN) for more than 7 days without multivitamins or dietary thiamin, or those on kidney dialysis.

Chronic alcoholism: In alcoholic or chronically malnourished patients, thiamin should always be administered before intravenous glucose solutions in order to avoid causing Wernicke's encephalopathy. All patients treated for alcohol withdrawal should be administered intravenous thiamin.

Metabolic disorders (Subacute necrotizing encephalopathy, Maple syrup urine disease, Pyruvate carboxylase deficiency, Hyperalaninemia)

Taking thiamin orally helps to temporarily correct some complications of metabolic disorders associated with genetic diseases including subacute necrotizing encephalopathy (SNE, Leigh's disease), maple syrup urine disease (branched-chain aminoacidopathy), and lactic acidosis associated with pyruvate carboxylase deficiency and hyperalaninemia. Long-term management should be under strict medical supervision.


Grade: A

Thiamin deficiency (Beriberi, Wernicke's encephalopathy, Korsakoff's psychosis, Wernicke-Korsakoff syndrome)

Humans are dependent on dietary intake to fulfill their thiamin requirements. Because there is very little thiamin stored in the body, depletion can occur as quickly as within 14 days. Severe chronic thiamin deficiency can result in potentially serious complications involving the nervous system/brain, muscles, heart, and gastrointestinal system.


Causes: Thiamin deficiency can result from inadequate thiamin intake (for example in chronic alcoholics, patients receiving intravenous feeding/parenteral nutrition for more than 7 days without multivitamins or dietary thiamin, or those living in countries with principally carbohydrate-based diets); increased body requirements for thiamin (such as with strenuous exercise, malaria, HIV infection, hyperthyroidism, fever, severe liver disease, pregnancy, breastfeeding, or adolescent growth); excessive loss of thiamin from the body (for example in patients with kidney failure on dialysis or those taking diuretics); or consumption of large amounts of anti-thiamin factors in foods (such as coffee, tea, betel nuts, vitamin C, raw freshwater fish, shellfish, ferns, or African silkworms).

Effects: Severe chronic thiamin deficiency can result in potentially serious complications involving the nervous system/brain, muscles, heart, and gastrointestinal system.Historically, the consequences of thiamin deficiency have been classified into three subtypes: 1)dryberiberi refers to neuromuscular complications such as peripheral neuropathy and weakness (including burning feet, exaggerated reflexes, diminished sensation and weakness in the legs and arms, muscle pains, and ultimately seizures in severe cases); 2)wetberiberi refers to cardiovascular complications such as rapid heart rate, pulmonary edema (water in the lungs), and heart failure/cardiomyopathy (Shoshin-type beriberi); and 3)cerebralberiberi refers to central nervous system (brain) complications such as Wernicke's encephalopathy (abnormal eye movements, stance/gait abnormalities, mental dysfunction), Korsakoff's psychosis (apathy, confusion, severe memory deficits/amnesia), or the combination of the two (Wernicke-Korsakoff syndrome).

Treatment: Patients diagnosed with Wernicke's encephalopathy, Korsakoff's psychosis, or Wernicke-Korsakoff syndrome should be treated immediately with intravenous thiamin. Therapy usually improves eye symptoms, but may not improve memory deficits or motor coordination, depending on the duration or severity of the thiamin deficiency. Lack of treatment may result in permanent neurologic damage or death. Thiamin supplementation should be considered in chronic alcoholics, and all patients treated for alcohol withdrawal should be administered intravenous thiamin. Thiamin should always be administered before intravenous glucose solutions in alcoholic or chronically malnourished patients, in order to avoid causing Wernicke's encephalopathy. It is not clear that thiamin is beneficial to reverse cardiovascular complications (wet beriberi), although thiamin supplementation may arrest the progression of heart damage. If heart failure is present, standard medical therapy for this condition should be administered.


Grade: A

Acute alcohol withdrawal

Patients with chronic alcoholism or experiencing alcohol withdrawal are at risk of thiamin deficiency and its associated complications, and should be administered thiamin. Thiamin should always be administered before intravenous glucose solutions in alcoholic or chronically malnourished patients (for example, 100mg IM or IV), in order to avoid causing Wernicke's encephalopathy.


Grade: B

Total parenteral nutrition (TPN)

Thiamin should be added to TPN formulations for patients who are unable to receive thiamin through other sources (such as a multivitamin) for more than 7 days. There are documented cases of lactic acidosis occurring in patients receiving TPN without thiamin.


Grade: B

Alzheimer's disease

Because thiamin deficiency can result in a form of dementia (Wernicke-Korsakoff syndrome), its relationship to Alzheimer's disease and other forms of dementia has been investigated. Whether thiamin supplementation is of benefit in Alzheimer's disease remains controversial. Some improvements in cognitive function have been reported in Alzheimer's patients taking thiamin. Further evidence is necessary before a firm conclusion can be reached.


Grade: C

Athletic performance

There is inconclusive scientific evidence in this area.


Grade: C

Cancer

Thiamin deficiency has been observed in some cancer patients, possibly due to increased metabolic needs. It is not clear if lowered levels of thiamin in such patients may actually be adaptive (beneficial). Currently, it remains unclear if thiamin supplementation plays a role in the management of any particular type(s) of cancer. A multivitamin including thiamin is generally considered to be reasonable in such patients, particularly in those with decreased dietary intake or anorexia.


Grade: C

Cataract prevention

Preliminary evidence from a population study suggests that high dietary thiamin intake may be associated with a decreased risk of cataracts (approximately 10mg thiamin daily). Further evidence is necessary before a firm conclusion can be reached.


Grade: C

Coma/hypothermia of unknown origin

Administration of 50-100mg IV or IM of thiamin is often recommended in patients with coma or hypothermia of unknown origin, due to the possible diagnosis of Wernicke's encephalopathy.


Grade: C

Crohn's disease

Decreased serum thiamine levels have been reported in patients with Crohn's disease. It is not clear if routine thiamin supplementation is beneficial in such patients generally.


Grade: C

Didmoad (Wolfram) syndrome

Didmoad (Wolfram) syndrome is a rare autosomal recessive inherited disease which results in diabetes mellitus, optic atrophy, diabetes insipidus, sensorineural deafness, and occasionally megaloblastic anemia. The defect is believed to cause a decrease in the enzyme that converts thiamin to its active form, thiamin pyrophosphate. Thiamin, at doses between 25-100mg, has been reported as effective in reversing anemia associated with Didmoad syndrome, within 2 weeks. Thiamin may also be effective in reducing or eliminating insulin requirements. Thiamin appears to be beneficial principally in patients with Didmoad syndrome with anemia. Management should be under strict medical supervision.


Grade: C

Heart failure (cardiomyopathy)

Chronic severe thiamin deficiency can cause heart failure (wet beriberi), a condition which merits thiamin supplementation. It is not clear that thiamin supplementation is beneficial in patients with heart failure due to other causes. However, it is reasonable for patients with heart failure to take a daily multivitamin including thiamin, because some of these individuals may be thiamin deficient.

Diuretics may lower thiamin levels, particularly high doses of loop diuretics such as furosemide (Lasix) 80 mg/day. Since diuretics are commonly administered to patients with heart failure, patients taking diuretics are at an increased risk of thiamin deficiency. This area remains controversial, and further evidence is necessary before a firm conclusion can be reached.


Grade: C

Pyruvate dehydrogenase deficiency (PDH)

There is preliminary evidence of clinical improvements in children with PDH following thiamin administration. Further evidence is necessary before a firm conclusion can be reached.


Grade: C

Subclinical thiamin deficiency in the elderly

While typically asymptomatic, the elderly have been found to have lower thiamin concentrations than younger people. There is limited evidence that thiamin supplementation may be beneficial in individuals with persistently low thiamin blood levels, yielding improved quality of life, decreased systolic blood pressure and decreased weight compared to placebo. Further study is necessary before a firm conclusion can be formed in this area.


Grade: C

Hip Fracture

Fractures of the hip are an important cause of later ill health and mortality in older people. People with hip fractures are often malnourished at the time of fracture, and have poor food intake in hospital. Preliminary evidence shows that supplemental thiamin is not beneficial for hip fractures.


Grade: D

Age-related lens opacification, Bell's palsy, canker sores, chronic diarrhea, circulation enhancement, depression, diabetes, diabetic nephropathy, dysmenorrheal (painful menstruation), epilepsy, erectile dysfunction, fibromyalgia, gastrointestinal disorders, HIV support, high blood pressure, insect repellant, learning, low back pain, memory enhancement, myelodysplasia, optic neuropathy, multiple sclerosis, poor appetite, protection from radiation-induced genetic changes, tissue healing after surgery, ulcerative colitis.