Thiamin (thiamine), vitamin B1

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Evidence

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. 		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. Patients with thiamin deficiency or related conditions should receive supplemental thiamin under medical supervision. 		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. 		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 seven days. 		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. Further evidence is necessary before a firm conclusion can be reached. 		C
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. 		C
Athletic performance
There is inconclusive scientific evidence in this area. 		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. 		C
Cataract prevention
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. 		C
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. 		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. 		C
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. 		C
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. Diuretics may lower thiamin levels. 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. 		C
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. 		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. 		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. Further study is necessary before a firm conclusion can be formed in this area. 		C
Fractures (hip)
Preliminary evidence shows that supplemental thiamin is not beneficial for hip fractures. 		D

Key to grades
A Strong scientific evidence for this use
B Good scientific evidence for this use
C Unclear scientific evidence for this use
D Fair scientific evidence against this use (it may not work)
F Strong scientific evidence against this use (it likely does not work)

Grading rationale

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Age-related lens opacification, Bell's palsy, brain damage (ifosfamide-induced encephalopathy), canker sores, chronic diarrhea, circulation improvement, depression, diabetes, diabetic nephropathy, dysmenorrhea (painful menstruation), epilepsy, erectile dysfunction, fibromyalgia, gastrointestinal disorders, high blood pressure, HIV support, insect repellant, learning, loss of appetite, low back pain, megaloblastic anemia, memory enhancement, myelodysplastic syndrome, optic nerve dysfunction (optic neuropathy), multiple sclerosis, radiation-induced damage (protection from genetic changes), tissue healing after surgery, ulcerative colitis.

Dosing Synonyms

NS_patient-thiamin

Portions of this document last updated:

Sept. 1, 2009

THIS EVIDENCE-BASED MONOGRAPH WAS PREPARED BY
THE NATURAL STANDARD RESEARCH COLLABORATION
(www.naturalstandard.com)


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