The EclecticPhysician

The Eclectic Physician
Vitamin and Mineral Information

Vitamin B-1/Thiamine

The information on this page compiled by
Beth Burch N.D.
(click on the keywords)


Vitamin B-1 or thiamine is an important part of an enzyme needed by every cell in the body for energy production and is especially important for proper nerve cell function. Mild and early deficiency of vitamin B-1 produces fatigue, irritability, poor memory, sleep disruption, decreased appetite and constipation. Severe deficiency of thiamine results in a condition known as beriberi. Dry beriberi is characterized by bilateral numbness and tingling of the lower extremities, with leg pains and burning feet. Cerebral beriberi, also known as Wernicke-Korsakoff syndrome or Wernicke’s encephalopathy is characterized by mental confusion and can result in permanent brain changes. Cardiovascular beriberi, also known as wet beriberi, causes congestive heart failure with edema and difficulty breathing. Deficiency is the result of inadequate intake and utilization of thiamine, and is especially common in alcoholics and with a poor diet. It is also seen frequently in any condition which affects intestinal absor ption or intake of thiamine, including malabsorption from Chron’s disease and excessive vomiting of pregnancy (hyperemesis gravidarum), also in some cancer patients and patients receiving intravenous nutrition without vitamin supplementation. Recent studies have found many elderly people have undiagnosed thiamine deficiency.

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  • Vitamin B-1 is most commonly available in supplement form as thiamine hydrochloride.

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Food Sources

  • Very good sources of vitamin B-1 include nutritional yeast, wheat germ, sunflower seeds, brown rice, soybeans and peanuts. Good sources include whole grains and nuts. Thiamine is inactivated by alcohol, sulfites and the tannins found in coffee and tea.

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  • Recommended Daily Allowance (RDA)
  • Infants- 0.3-0.4 mg
  • Children (ages 1-10)- 0.7-1.0 mg
  • Adults- 1.0-1.5 mg
  • Pregnancy- 1.5 mg
  • Lactation- 1.6 mg

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Optimal Supplementation

  • 10-30 mg per day

Treatment of Health Conditions

  • 50-100 mg per day
  • For severe deficiency 100 mg intravenously daily

Conditions used for

  • Wernicke’s encephalopathy (4, 5, 6)
  • Peripheral neuropathy (2, 4)
  • Congestive heart failure from thiamine deficiency (3)
  • Alzheimer’s disease (7, 8)
  • Chronic fatigue syndrome ()
  • Canker sores (1,10)
  • Thiamine deficiency

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Side effects

  • Nausea with large doses
  • Sweating, sensation of warmth

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  • Hypersensitivity to thiamine products

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Interactions with other nutrients

  • Works together with other B vitamins in energy production in the body
  • Magnesium is required to convert thiamine to its active form
  • Interactions with medications and herb
  • Inhibited by phenytoin and alcohol
  • Furosemide increases urinary excretion of thiamine (9)

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1. Haisraeli-Shalish M et al, Recurrent aphthous stomatitis and thiamine deficiency, Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996;82(6):634-6
2. Djoenaidi W et al, Subclinical beriberi polyneuropathy in the low income group: an investigation with special tools on possible patients with suspected complaints, Eur J Clin Nutr 1996;50(8):549-55
3. te Water W et al, Failure in self care and heart failure, thiamine deficiency in geriatric patients, Tijdschr Gerontol Geriatr 1996;27(3):97-101
4. Kril JJ, Neuropathology of thiamine deficiency disorders, Metab Brain Dis 1996;11(1):9-17
5. Hahn JS et al, Wernicke encephalopathy and beriberi during total parenteral nutrition
attributable to multivitamin infusion shortage, Pediatrics 1998;101(1):E10
6. Andersson JE, Wernicke's encephalopathy, Ugeskr Laeger 1996;158(7):898-901
7. Gold M et al, Plasma thiamine deficiency associated with Alzheimer's disease but not Parkinson's disease, Metab Brain Dis 1998;13(1):43-53
8. Gold M et al, Plasma and red blood cell thiamine deficiency in patients with dementia of the Alzheimer's type, Arch Neurol 1995;52(11):1081-6
9. Rieck J et al, Urinary loss of thiamine is increased by low doses of furosemide in healthy volunteers, J Lab Clin Med 1999;134(3):238-43
10. Nolan A et al, Recurrent aphthous ulceration: vitamin B1, B2 and B6 status and response to replacement therapy, J Oral Pathol Med 1991;20(8):389-91

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* The information presented in this web site is intended to inform and educate. It is not intended replace a qualified medical practitioner to diagnose or treat medical conditions.

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