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.
Severe chronic thiamin deficiency (beriberi) can result in potentially serious complications involving the nervous system/brain, muscles, heart, and gastrointestinal system.
Dietary sources of thiamin include beef, brewer's yeast, legumes (beans, lentils), milk, nuts, oats, oranges, pork, rice, seeds, wheat, whole grain cereals, and yeast. In industrialized countries, foods made with white rice or white flour are often fortified with thiamin (because most of the naturally occurring thiamin is lost during the refinement process).
Aneurine, aneurine HCL, aneurine mononitrate, antiberiberi factor, antiberiberi vitamin, antineuritic factor, antineuritic vitamin, anurine, B complex vitamin, beta-hydroxy-ethylthiazolium chloride, thiamin, thiamin chloride, thiamin diphosphate, thiamin HCL, thiamin hydrochloride, thiamin monophosphate (TMP), thiamin nitrate, thiamin pyrophosphate (TPP), thiamin triphosphate (TTP), thiamine, thiamine chloride, thiaminium chloride HCL, thiaminium chloride hydrochloride.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Metabolic disorders (subacute necrotizing encephalopathy, maple syrup urine disease, pyruvate carboxylase deficiency, hyperalaninemia)
Taking thiamin by mouth 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.
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. Patients with thiamin deficiency or related conditions should receive supplemental thiamin under medical supervision.
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.
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 seven days.
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. Further evidence is necessary before a firm conclusion can be reached.
Atherosclerosis (prevention in patients with acute hyperglycemia, impaired glucose tolerance (IGT), and diabetes mellitus)
Patients with diabetes are at risk of developing hardened arteries (called atherosclerosis). This happens when cholesterol and other substances build up and clog the arteries. Thiamin has been studied as a way to help widen arteries that are too narrow. Regular intake of thiamin might help slow the progression of atherosclerosis. However, additional research is needed.
There is inconclusive scientific evidence in this area.
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.
Preliminary evidence suggests that high dietary thiamin intake may be associated with a decreased risk of cataracts. Further evidence is necessary before a firm conclusion can be reached.
Coma/hypothermia of unknown origin
Administration of thiamin is often recommended in patients with coma or hypothermia of unknown origin, due to the possible diagnosis of Wernicke's encephalopathy.
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.
Didmoad (Wolfram) syndrome
Didmoad (Wolfram) syndrome is a rare autosomal recessive inherited disease that 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. Management, including thiamin supplementation, should be under strict medical supervision.
Heart failure (cardiomyopathy)
Chronic severe thiamin deficiency can cause heart failure (wet beriberi), a condition that 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.
Leg cramps (during pregnancy)
Vitamin B supplements have been used to treat leg cramps during pregnancy. However, additional studies are needed to determine if it is effective.
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.
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. Further study is necessary before a firm conclusion can be formed in this area.
Preliminary evidence shows that supplemental thiamin is not beneficial for hip fractures.