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

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

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