Thiamine (Vitamin B1) Deficiency Symptoms, Causes & Treatment

Vitamin B1 (Thiamin): Foods, benefits, and deficiency symptoms

Thiamine (Vitamin B1) Deficiency Symptoms, Causes & Treatment

  • Foods
  • Benefits
  • Deficiency symptoms
  • Function
  • Side effects

Vitamin B1, thiamin, or thiamine, enables the body to use carbohydrates as energy. It is essential for glucose metabolism, and it plays a key role in nerve, muscle, and heart function.

Vitamin B1 is a water-soluble vitamin, as are all vitamins of the B complex.

Vitamins are classified according to the materials they dissolve in. Some dissolve in water, and others dissolve in fat. Water-soluble vitamins are carried through the bloodstream. Whatever the body does not use is eliminated in urine.

Share on PinterestMeat, fish, and grains are a good source of Vitamin B1

There are high concentrations of Vitamin B1 in the outer layers and germ of cereals, as well as in yeast, beef, pork, nuts, whole grains, and pulses.

Fruit and vegetables that contain it include cauliflower, liver, oranges, eggs, potatoes, asparagus, and kale.

Other sources include brewer’s yeast and blackstrap molasses.

Breakfast cereals and products made with white flour or white rice may be enriched with vitamin B.

In the United States, people consume around half of their vitamin B1 intake in foods that naturally contain thiamin, while the rest comes from foods that are fortified with the vitamin.

Heating, cooking, and processing foods, and boiling them in water, destroy thiamin. As vitamin B1 is water-soluble, it dissolves into cooking water. White rice that is not enriched will contain only one tenth of the thiamin available in brown rice.

The National Institutes of Health (NIH) Office of Dietary Supplements (ODS) note that one serving of fortified breakfast cereal provides 1.5 milligrams (mg) of thiamin, which is more than 100 percent of the daily recommended amount.

One slice of whole wheat bread contains 0.1 mg, or 7 percent of the daily requirement. Cheese, chicken, and apples contain no thiamin.

Humans need a continuous supply of vitamin B1, because it is not stored in the body. It should be part of the daily diet.

Vitamin B1, or thiamin, helps prevent complications in the nervous system, brain, muscles, heart, stomach, and intestines. It is also involved in the flow of electrolytes into and muscle and nerve cells.

It helps prevent diseases such as beriberi, which involves disorders of the heart, nerves, and digestive system.

Uses in medicine

Patients who may receive thiamin to treat low levels of vitamin B1 include those with peripheral neuritis, which is an inflammation of the nerves outside the brain, or pellagra.

People with ulcerative colitis, persistent diarrhea, and poor appetite may also receive thiamin. Those who are in a coma may be given thiamin injections.

Some athletes use thiamin to help improve their performance. It is not a prohibited substances for athletes in the U.S.

Other conditions in which thiamin supplements may help include:

Not all of these uses have been definitively confirmed by research.

A deficiency of vitamin B1 commonly leads to beriberi, a condition that features problems with the peripheral nerves and wasting.

Weight loss and anorexia can develop.

There may be mental problems, including confusion and short-term memory loss.

Muscles may become weak, and cardiovascular symptoms can occur, for example, an enlarged heart.

How much vitamin B1 do we need?

In the U.S., the recommended daily allowance (RDA) of thiamin taken by mouth is 1.2 mg for males and 1.1 mg for females over the age of 18 years. Pregnant or breastfeeding women of any age should consume 1.4 mg each day.

Who is at risk of B1 deficiency?

People with poor diet, cancer, “morning sickness” during pregnancy, bariatric surgery, and hemodialysis are at risk of thiamin deficiency.

People who regularly drink alcohol to excess may have a deficiency, as they may not absorb thiamin from their food.

Wernicke-Korsakoff syndrome is a disorder that affects people with chronic alcoholism. It is linked to a lack of thiamin, and it can be fatal if not treated.

People with Wernicke-Korsakoff syndrome and those who are withdrawing from alcohol may receive thiamin injections to help them recover.

Other diseases, such as HIV, can reduce the absorption of nutrients, and this can lead to a deficiency of vitamin B1.

All B vitamins are water-soluble. They help to convert carbohydrates, fats, and protein into energy, or glucose.

B vitamins are necessary for keeping the liver, skin, hair, and eyes healthy. They also play a role in the nervous system, and they are needed for good brain function.

The B vitamins are sometimes called anti-stress vitamins, because they boost the body’s immune system in times of stress.

Evidence does not confirm any harm from too much vitamin B1, but the U.S. Food and Drug Administration (FDA) warns on the use of supplements.

They urge people to check with their health care provider before using supplements with or as a substitute for foods, and they call on the public to seek a physician’s advice on how to improve their health, rather than self-diagnosing.


Tea and coffee contain tannins, chemicals that may interact with thiamin, making it harder to absorb.

Some of the chemicals in raw shellfish and fish can destroy thiamin, potentially leading to a deficiency if eaten in large quantities. Cooking destroys these chemicals, but it destroys thiamin too.


Beriberi (Thiamine Deficiency) Treatment & Management: Approach Considerations, Activity

Thiamine (Vitamin B1) Deficiency Symptoms, Causes & Treatment

  1. Wooley, JA. Characteristics of thiamin and its relevance to the management of heart failure. Nutr Clin Pract. Oct-Nov 2008. 23:487-93. [Medline].

  2. Isselbacher KJ, Braunwald E, Wilson JD. Harrison's Principles of Internal Medicine. 13th ed. New York, NY: McGraw-Hill; 1994. 474-475.

  3. McCormick DB. Shils ME, Young VR, eds. Modern Nutrition in Health and Disease. Philadelphia, Pa: Lea and Febiger; 1988. 355-61.

  4. Rosen P, Barkin R. Emergency Medicine: Concepts and Clinical Practice. 4th ed. St. Louis, Mo: Mosby Year Book; 1998. 2138-40.

  5. Thiamine. Monograph. Altern Med Rev. 2003 Feb. 8(1):59-62. [Medline].

  6. Beers MH, Berkow R, Bogin RM, eds. The Merck Manual. 17th ed. Whitehouse Station, NJ: Merck & Co; 1999. 45-6.

  7. Cole PD, Kamen BA. “Beriberi” interesting!. J Pediatr Hematol Oncol. 2003 Dec. 25(12):924-6. [Medline].

  8. National Academy of Sciences. Dietary Guidance: Dietary Reference Intake Reports. USDA National Agricultural Library. Available at

  9. The National Academies Press. Nutrition – Dietary Reference Intakes: DRIs): Recommended Dietary Allowances and Adequate Intakes, Vitamins. Available at Files/Nutrition/DRIs/RDA and AIs_Vitamin and Elements.pdf. Accessed: July 27, 2011.

  10. Lu J, Frank EL. Rapid HPLC measurement of thiamine and its phosphate esters in whole blood. Clin Chem. 2008 May. 54(5):901-6. [Medline].

  11. Karuppagounder SS, Xu H, Pechman D, et al. Translocation of amyloid precursor protein C-terminal fragment(s) to the nucleus precedes neuronal death due to thiamine deficiency-induced mild impairment of oxidative metabolism. Neurochem Res. 2008 Mar 4. [Medline].

  12. Vasan S, Dulebohn SC. Wernicke Encephalopathy. 2018 Jan. [Medline]. [Full Text].

  13. Indraccolo U, Gentile G, Pomili G, et al. Thiamine deficiency and beriberi features in a patient with hyperemesis gravidarum. Nutrition. 2005 Sep. 21(9):967-8. [Medline].

  14. Zuccoli G, Gallucci M, Capellades J, et al. Wernicke encephalopathy: MR findings at clinical presentation in twenty-six alcoholic and nonalcoholic patients. AJNR Am J Neuroradiol. 2007 Aug. 28(7):1328-31. [Medline].

  15. Hazell AS. Astrocytes are a major target in thiamine deficiency and Wernicke's encephalopathy. Neurochem Int. 2009 Jul-Aug. 55(1-3):129-35. [Medline].

  16. Zuccoli G, Pipitone N. Neuroimaging findings in acute Wernicke's encephalopathy: review of the literature. AJR Am J Roentgenol. 2009 Feb. 192(2):501-8. [Medline].

  17. Masumoto K, Esumi G, Teshiba R, et al. Need for thiamine in peripheral parenteral nutrition after abdominal surgery in children. JPEN J Parenter Enteral Nutr. 2009 Jul-Aug. 33(4):417-22. [Medline].

  18. Matrana MR, Davis WE. Vitamin deficiency after gastric bypass surgery: a review. South Med J. October/ 2009. 102:1025-31. [Medline].

  19. Ahmed A, Daida Y, Novotny R. PS2-02: Micronutrient Deficiencies After Bariatric Surgery: Does Ethnicity Matter?. Clin Med Res. 2011 Nov. 9(3-4):165. [Medline].

  20. Francini-Pesenti F, Brocadello F, Manara R, Santelli L, Laroni A, Caregaro L. Wernicke's syndrome during parenteral feeding: not an unusual complication. Nutrition. February 2009. 25:142-6. [Medline].

  21. Braverman LE, Utiger RD. Werner and Ingbar's The Thyroid: A Fundamental and Clinical Text. 7th ed. Baltimore, Md: Lippincott Williams & Wilkins; 1996. 694, 864.

  22. Sriram K, Manzanares W, Joseph K. Thiamine in nutrition therapy. Nutr Clin Pract. 2012 Feb. 27(1):41-50. [Medline].

  23. Al-Attas OS, Al-Daghri NM, Alfadda A, Abd Al-Rahman SH, Sabico S. Blood Thiamine and Derivatives as measured by High-Performance Liquid Chromatography: Levels and Associations in DM Patients with Varying Degrees of Microalbuminuria. J Endocrinol Invest. 2011 Nov 22. [Medline].

  24. Wiesen P, Van Overmeire L, Delanaye P, Dubois B, Preiser JC. Nutrition disorders during acute renal failure and renal replacement therapy. J Parenter Enteral Nutr. March 2011. 35:217-22. [Medline].

  25. Sica DA. Loop diuretic therapy, thiamine balance, and heart failure. Congest Heart Fail. 2007 Jul-Aug. 13(4):244-7. [Medline].

  26. Hanninen SA, Darling PB, Sole MJ, et al. The prevalence of thiamin deficiency in hospitalized patients with congestive heart failure. J Am Coll Cardiol. 2006 Jan 17. 47(2):354-61. [Medline].

  27. Aasheim ET, Bjorkman S, Sovik TT, et al. Vitamin status after bariatric surgery: a randomized study of gastric bypass and duodenal switch. Am J Clin Nutr. 2009 Jul. 90(1):15-22. [Medline].

  28. Rao SN, Mani S, Madap K, et al. High prevalence of infantile encephalitic beriberi with overlapping features of Leigh's disease. J Trop Pediatr. 2008 May 8. [Medline].

  29. Fattal-Valevski A, Azouri-Fattal I, Greenstein YJ, et al. Delayed language development due to infantile thiamine deficiency. Dev Med Child Neurol. 2009 Aug. 51(8):629-34. [Medline].

  30. Nath A, Tran T, Shope TR, Koch TR. Prevalence of clinical thiamine deficiency in individuals with medically complicated obesity. Nutr Res. 2017 Jan. 37:29-36. [Medline].

  31. Weise Prinzo Z, de Benoist B. Meeting the challenges of micronutrient deficiencies in emergency-affected populations. Proc Nutr Soc. 2002 May. 61(2):251-7. [Medline].

  32. Whitfield KC, Smith G, Chamnan C, et al. High prevalence of thiamine (vitamin B1) deficiency in early childhood among a nationally representative sample of Cambodian women of childbearing age and their children. PLoS Negl Trop Dis. 2017 Sep. 11 (9):e0005814. [Medline]. [Full Text].

  33. Harel Y, Zuk L, Guindy M, Nakar O, Lotan D, Fattal-Valevski A. The effect of subclinical infantile thiamine deficiency on motor function in preschool children. Matern Child Nutr. 2017 Oct. 13 (4):[Medline].

  34. Shenoy VV, Patil PV, Nagar VS, et al. Congestive cardiac failure and anemia in a 15-year-old boy. J Postgrad Med. 2005 Jul-Sep. 51(3):225-7. [Medline].

  35. Karaiskos I, Katsarolis I, Stefanis L. Severe dysphagia as the presenting symptom of Wernicke-Korsakoff syndrome in a non-alcoholic man. Neurol Sci. February 2008. 29:45-6. [Medline].

  36. Isenberg-Grzeda E, Shen MJ, Alici Y, Wills J, Nelson C, Breitbart W. High rate of thiamine deficiency among inpatients with cancer referred for psychiatric consultation: results of a single site prevalence study. Psychooncology. 2016 May 26. [Medline].

  37. Jain A, Mehta R, Al-Ani M, Hill JA, Winchester DE. Determining the Role of Thiamine Deficiency in Systolic Heart Failure: A Meta-Analysis and Systematic Review. J Card Fail. 2015 Dec. 21 (12):1000-7. [Medline].

  38. Angstadt JD, Bodziner RA. Peripheral polyneuropathy from thiamine deficiency following laparoscopic Roux-en-Y gastric bypass. Obes Surg. 2005 Jun-Jul. 15(6):890-2. [Medline].

  39. Koike H, Iijima M, Mori K, et al. Postgastrectomy polyneuropathy with thiamine deficiency is identical to beriberi neuropathy. Nutrition. 2004 Nov-Dec. 20(11-12):961-6. [Medline].

  40. Edwards KA, Tu-Maung N, Cheng K, Wang B, Baeumner AJ, Kraft CE. Thiamine Assays-Advances, Challenges, and Caveats. ChemistryOpen. 2017 Apr. 6 (2):178-91. [Medline].

  41. Tran HA. Increased troponin I in “wet” beriberi. J Clin Pathol. 2006 May. 59(5):555. [Medline].

  42. Falder S, Silla R, Phillips M, Rea S, Gurfinkel R, Baur E, et al. Thiamine supplementation increases serum thiamine and reduces pyruvate and lactate levels in burn patients. Burns. 2010 Mar. 36(2):261-9. [Medline].

  43. Donnino M. Gastrointestinal beriberi: a previously unrecognized syndrome. Ann Intern Med. 2004 Dec 7. 141(11):898-9. [Medline].

  44. Wani NA, Qureshi UA, Ahmad K, Choh NA. Cranial Ultrasonography in Infantile Encephalitic Beriberi: A Useful First-Line Imaging Tool for Screening and Diagnosis in Suspected Cases. AJNR Am J Neuroradiol. 2016 Aug. 37 (8):1535-40. [Medline].


Vitamin B1 (Thiamine)

Thiamine (Vitamin B1) Deficiency Symptoms, Causes & Treatment

Vitamin B1, also called thiamine or thiamin, is one of 8 B vitamins. All B vitamins help the body convert food (carbohydrates) into fuel (glucose), which the body uses to produce energy.

These B vitamins, often referred to as B-complex vitamins, also help the body metabolize fats and protein. B-complex vitamins are needed for a healthy liver, skin, hair, and eyes.

They also help the nervous system function properly and are needed for good brain function.

All B vitamins are water soluble, meaning that the body does not store them.

other B-complex vitamins, thiamine is sometimes called an “anti-stress” vitamin because it may strengthen the immune system and improve the body's ability to withstand stressful conditions. It is named B1 because it was the first B vitamin discovered.

Thiamine is found in both plants and animals and plays a crucial role in certain metabolic reactions. Your body needs it to form adenosine triphosphate (ATP), which every cell of the body uses for energy.

It is rare to be deficient in thiamine, although alcoholics, people with Crohn disease, anorexia, and those undergoing kidney dialysis may be deficient. Symptoms of thiamine deficiency are:

  • Headache
  • Nausea
  • Fatigue
  • Irritability
  • Depression
  • Abdominal discomfort

People with thiamine deficiency also have trouble digesting carbohydrates. This allows a substance called pyruvic acid to build up in the bloodstream, causing a loss of mental alertness, difficulty breathing, and heart damage, a disease known as beriberi.


The most important use of thiamine is to treat beriberi, which is caused by not getting enough thiamine in your diet. Symptoms include:

  • Swelling, tingling, or burning sensation in the hands and feet
  • Confusion
  • Trouble breathing because of fluid in the lungs
  • Uncontrolled eye movements (nystagmus)

People in the developed world usually do not get beriberi because foods such as cereals and breads are fortified with vitamin B1.

Wernicke-Korsakoff syndrome

Wernicke-Korsakoff syndrome is a brain disorder caused by thiamine deficiency. Wernicke-Korsakoff is actually two disorders. Wernicke disease involves damage to nerves in the central and peripheral nervous systems.

It is often caused by malnutrition due to alcoholism. Korsakoff syndrome is characterized by memory problems and nerve damage.

High doses of thiamine can improve muscle coordination and confusion, but rarely improves memory loss.


Preliminary evidence suggests that thiamine, along with other nutrients, may lower the risk of developing cataracts.

People with plenty of protein and vitamins A, B1, B2, and B3 (or niacin) in their diet are less ly to develop cataracts.

Getting enough vitamins C, E, and B complex vitamins, particularly B1, B2, B9 (folic acid), and B12, may further protect the lens of your eyes from developing cataracts. More research is needed.

Alzheimer disease

Lack of thiamine can cause dementia in Wernicke-Korsakoff syndrome. So researchers have speculated that thiamine might help Alzheimer disease. Oral thiamine has been shown to improve cognitive function of patients with Alzheimer. However, absorption of thiamine is poor in elderly individuals. More research is needed before thiamine can be proposed as a treatment for Alzheimer disease.

Heart failure

Thiamine may be related to heart failure because many people with heart failure take diuretics (water pills), which help rid the body of excess fluid. But diuretics may also cause the body to get rid of too much thiamine. A few small studies suggest that taking thiamine supplements may help. Taking a daily multivitamin should provide enough thiamine.


Low levels of thiamine are associated with depression. In one study of elderly Chinese adults, poor thiamine levels were associated with a higher risk of depression.

Most foods contain small amounts of thiamine. Large amounts can be found in:

  • Pork
  • Beef
  • Poultry
  • Organ meats

Other good dietary sources of thiamine include:

  • Whole-grain or enriched cereals and rice
  • Legumes
  • Wheat germ
  • Bran
  • Brewer's yeast
  • Nuts
  • Blackstrap molasses

Vitamin B1 can be found in multivitamins (including children's chewable and liquid drops), B complex vitamins, or it can be sold individually. It is available in a variety of forms, including tablets, soft gels, and lozenges. It may also be labeled as thiamine hydrochloride or thiamine mononitrate. In cases of severe deficiency, thiamine can be administered intravenously.

As with all medications and supplements, check with your health care provider before giving vitamin B1 supplements to a child.

Daily recommendations for dietary vitamin B1, according to the National Academy of Sciences, are as follows:


  • Newborns, 6 months: 0.2 mg (adequate intake)
  • Infants, 7 months to 1 year: 0.3 mg (adequate intake)
  • Children, 1 to 3 years: 0.5 mg (RDA)
  • Children, 4 to 8 years: 0.6 mg (RDA)
  • Children, 9 to 13 years: 0.9 mg (RDA)
  • Men, 14 to 18 years: 1.2 mg (RDA)
  • Women, 14 to 18 years: 1 mg (RDA)


  • Men, 19 years and older: 1.2 mg (RDA)
  • Women, 19 years and older: 1.1 mg (RDA)
  • Pregnant or breastfeeding women: 1.4 mg (RDA)

Doctors determine the appropriate doses for conditions beriberi and Wernicke-Korsakoff syndrome. Doctors give thiamine intravenously for Wernicke-Korsakoff syndrome.

A daily dose of 50 to 100 mg is often taken as a supplement. Thiamine appears safe in these doses. But you should talk to your doctor before taking a large amount.

Because of the potential for side effects and interactions with medications, you should take dietary supplements only under the supervision of a knowledgeable health care provider.

Thiamine is generally safe. Very high doses may cause stomach upset.

Taking any one of the B vitamins for a long period of time can result in an imbalance of other important B vitamins. For this reason, you may want to take a B-complex vitamin, which includes all the B vitamins.

If you are currently taking any of the following medications, you should not use vitamin B1 without first talking to your doctor.

Digoxin: Laboratory studies suggest that digoxin, a medication used to treat heart conditions, may reduce the ability of heart cells to absorb and use vitamin B1. This may be particularly true when digoxin is combined with furosemide (Lasix, a loop diuretic).

Diuretics (water pills): Diuretics, particularly furosemide (Lasix), which belongs to a class called loop diuretics, may reduce levels of vitamin B1 in the body. It is possible that other diuretics may have the same effect. If you take a diuretic, ask your doctor if you need a thiamine supplement.

Phenytoin (Dilantin): Preliminary evidence suggests that some people taking phenytoin have lower levels of thiamine in their blood, which may contribute to the side effects of the drug. However, this is not true of all people who take phenytoin. If you take phenytoin, ask your doctor if you need a thiamine supplement.

Ambrose, ML, Bowden SC, Whelan G. Thiamin treatment and working memory function of alcohol-dependent people: preliminary findings. Alcohol Clin Exp Res. 2001;25(1):112-16.

Bonucchi J, Hassan I, Policeni B, Kaboli P. Thyrotoxicosis associated with Wernicke's encephalopathy. J Gen Intern Med. 2008;23(1):106-109.

Bruno EJ Jr, Ziegenfuss TN. Water-soluble vitamins: research update. Curr Sports Med Rep. 2005 Aug;4(4):207-13. Review.

Costantini A, Pala MI. Thiamine and fatigue in inflammatory bowel diseases: an open-label pilot study. J Altern Complement Med. 2013;19(8):704-8.

Cumming RG, Mitchell P, Smith W. Diet and cataract: the Blue Mountains Eye Study.Ophthalmology. 2000;107(3):450-56.

Daroff. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012.

DiNicolantonio JJ, Niazi AK, Lavie CJ, O'Keefe JH, Ventura HO. Thiamine supplementation for the treatment of heart failure: a review of the literature. Congest Heart Fail. 2013;19(4):214-22.

Gibson GE, Blass JP. Thiamine-dependent processes and treatment strategies in neurodegeneration. Antioxid Redox Signal. 2007 Aug 8; [Epub ahead of print].

Isenberg-Grzeda E, Chabon B, Nicolson SE. Prescribing thiamine to impatients with alcohol use disorders: how well are we doing? J Addict Med. 2014;8(1):1-5.

Jacques PF, Chylack LT Jr, Hankinson SE, et al. Long-term nutrient intake and early age-related nuclear lens opacities. Arch Ophthalmol. 2001;119(7):1009-19.

Kliegman: Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 46.

Kuzniarz M, Mitchell P, Cumming RG, Flood VM. Use of vitamin supplements and cataract: the Blue Mountains Eye Study. Am J Ophthalmol. 2001;132(1):19-26.

Lonsdale D. A review of the biochemistry, metabolism and clinical benefits of thiamin(e) and its derivatives. Evid Based Complement Alternat Med. 2006 Mar;3(1):49-59.

Lu'o'ng K, Nguyen LT. Role of thiamine in Alzheimer's disease. Am J Alzheimers Dis Other Demen. 2011;26(8):588-98.

McPherson & Pincus: Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, PA: Elsevier Saunders; 2007.

Moonen M, Lancellotti P, Betz R, Lambermont B, Pierard L. Beriberi. Rev Med Liege. 2007;62(7-8):523-30.

National Academy of Sciences. Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Vitamins. Accessed June 1, 2011.

Raschke M, et al. Vitamin B1 biosynthesis in plants requires the essential iron sulfur cluster protein, THIC. Proc Natl Acad Sci. USA. 2007;104(49):19637-42.

Rodriquez-Martin JL, Qizilbash N, Lopez-Arrieta JM. Thiamine for Alzheimer's disease (Cochrane Review). Cochrane Database Syst Rev. 2001;2:CD001498.

Roman-Campos D, Cruz JS. Current aspects of thiamine deficiency on heart function. Life Sci. 2014;98(1):1-5.

Sarma S, Gheorghiade M. Nutritional assessment and support of the patient with acute heart failure. Curr Opin Crit Care. 2010 Oct;16(5):413-18. Review.

Sica DA. Loop diuretic therapy, thiamine balance, and heart failure. Congest Heart Fail. 2007 Jul-Aug;13(4):244-47.

Soukoulis V, Dihu JB, Sole M, Anker SD, Cleland J, Fonarow GC, Metra M, Pasini E, Strzelczyk T, Taegtmeyer H, Gheorghiade M. Micronutrient deficiencies an unmet need in heart failure. J Am Coll Cardiol. 2009 Oct 27;54(18):1660-1673. Review.

Thomson AD, Marshall EJ. The treatment of patients at risk of developing Wernicke's encephalopathy in the community. Alcohol. 2006 Mar-Apr;41(2):159-67. Epub 2005 Dec 29.

Thompson J. Vitamins, minerals and supplements: part two. Community Pract. 2005 Oct;78(10):366-8. Review.

Witte KK, Clark AL, Cleland JG. Chronic heart failure and micronutrients. J Am Coll Cardiol. 2001;37(7):1765-74.

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Vitamin B1 Thiamine Deficiency (Beriberi)

Thiamine (Vitamin B1) Deficiency Symptoms, Causes & Treatment

Thiamine was the first vitamin identified (vitamin B1) many years ago.

It functions as a catalyst in the generation of energy through decarboxylation of branched-chain amino acids and alpha-ketoacids and acts as a coenzyme for transketolase reactions in the form of thiamine pyrophosphate. Thiamine also plays an unidentified role in the propagation of nerve impulses and takes part in myelin sheath maintenance.[1]

This water-soluble vitamin is present in meat, beef, pork, legumes, whole grains, and nuts; however, milled rice and grains have little amounts of thiamine as the processing involved in creating these food products removes thiamine. Additionally, certain food products such as tea, coffee, raw fish, and shellfish, contain thiaminases – enzymes that destroy thiamine.

Deficiency of thiamine can affect the cardiovascular, nervous, and immune system, as is commonly seen in wet beriberi, dry beriberi, or as Wernicke-Korsakoff syndrome.

  Worldwide it is most widely reported in populations where polished rice and milled cereals are the primary food source, and also in patients with chronic alcohol abuse. Dry beriberi presents as symmetrical peripheral neuropathy while wet beriberi presents with high-output heart failure.

  Wernicke-Korsakoff syndrome (WKS) can manifest with CNS symptoms such as gait changes, altered mental status, and ocular abnormalities.[2]

Deficiency of thiamine can be related to [3]:

Poor intake

  • Diets primarily high in polished rice/processed grains
  • Chronic alcoholism
  • Parental nutritional without adequate thiamine supplementation
  • Gastric bypass surgery

Poor absorption

  • Malnutrition
  • Gastric bypass surgery
  • Malabsorption syndrome

Increased loss 

  • Diarrhea
  • Hyperemesis gravidarum
  • Diuretic use
  • Renal replacement therapy

Increased thiamine utilization

  • Pregnancy
  • Lactation
  • Hyperthyroidism
  • Refeeding syndrome

Drugs that can lead to thiamine deficiency


Worldwide, thiamine deficiency is primarily due to inadequate dietary intake, specifically in diets comprised mainly of polished rice and grains. In Western countries, it most commonly presents in patients suffering from alcoholism or chronic illness.

Special populations of individuals also at risk for thiamine deficiency include pregnant women, those requiring parental feeding, individuals who have undergone bariatric surgery, those with overall poor nutritional status, and patients on chronic diuretic therapy as it increases urinary losses.

Deficiency of this vitamin in women can cause infantile beriberi, which this article will not specifically address.[4]

When thiamine stores are depleted (which takes about 4 weeks after stopping intake), symptoms start to appear.

Dry beriberi occurs when the CNS is involved. This condition is usually due to poor intake. The neurological features include impaired reflexes and symmetrical motor and sensory deficits in the extremities. Loss of myelin is seen without any acute inflammation.

Another variation of dry beriberi is Wernicke encephalopathy.

This condition presents in well-defined steps starting with nausea and vomiting, followed by horizontal nystagmus, ocular nerve palsy, fever, ataxia, and progressive mental impairment, eventually leading to the korsakoff syndrome. Improvement is only possible if the patient has not developed the korsakoff syndrome. Less than 50% of patients show significant recovery after treatment.

Wet beriberi is present when the cardiovascular system is involved. The heart fails to function, leading to edema and fluid retention. The key reason for heart dysfunction is an overuse injury.

Wet beriberi is a medical emergency and without treatment can lead to death within days.

Thiamine can slowly help with recovery but most patients do require intense supportive measures in an ICU setting.


When evaluating for thiamine deficiency, the typical history may include poor nutritional intake, excessive alcohol intake, or the patient belonging to the special populations of individuals previously mentioned (pregnant women, recipients of bariatric surgery, patients with prolonged diuretic use, anyone with poor overall nutritional status, etc.).  

Initial symptoms of B1 deficiency include anorexia, irritability, and difficulties with short-term memory.

With prolonged thiamine deficiency, patients may endorse loss of sensation in the extremities,  symptoms of heart failure including swelling of the hands or feet and chest pain related to demand ischemia, or feelings of vertigo, double vision, and memory loss.  Additionally, close friends and family of the patient may describe confusion or symptoms of confabulation. 

Physical Exam

Dry beriberi:

  • Evidence of symmetric peripheral neuropathy with motor and sensory changes
  • Diminished reflexes

Wet beriberi – cardiovascular compromise related to impaired myocardial energy metabolism and dysautonomia:

  • Dilated cardiomyopathy
  • Tachycardia
  • High-output congestive heart failure
  • Peripheral edema

Wet and dry beriberi often have overlapping features, and in either condition, paresthesias may be a presenting feature.

Wernicke’s encephalopathy (WE) is a classic triad of ocular abnormalities (nystagmus, ophthalmoplegia), confusion, and gait changes such as ataxia.

Wernicke’s encephalopathy with additional symptoms of memory loss and psychosis with confabulation is consistent with WKS.[1][5]

Detection of thiamine deficiency relies on relevant history and physical exam findings and follow up with laboratory testing for confirmation.[6]Laboratory Studies:

  • Functional enzymatic assay of transketolase activity – the activity of transketolase is measured before and after the addition of thiamine pyrophosphate; >25% stimulation response is abnormal
  • Measurement of thiamine or the phosphorylated esters of thiamine in serum or blood using high-performance liquid chromatography
  • Urine studies exist but are not a reliable test for the evaluation of total body thiamine
  • Metabolic acidosis can occur with thiamine deficiency, due to the accumulation of lactate

Consider other diagnostic studies presentation and comorbid conditions (transthoracic echo or TSH measurements in new heart failure, for example).

Radiographic Studies:

MR: most common abnormalities seen with WE are symmetric changes in the thalamus, mamillary bodies, periaqueductal area, and tectal plate.[7]

Treatment of acute thiamine deficiency with cardiovascular or neurologic signs/symptoms [4]: 

200mg intravenous (IV) or orally (PO) thiamine three times daily until symptoms resolve or improvement plateaus, at which time the patient should transition to 10mg/day oral thiamine until expected recovery is complete.

Another option in acute crisis is 50mg administered intramuscularly for 2-4 days, followed by oral maintenance therapy

Treatment of thiamine deficiency with suspected WKS [8]: 

  • 500mg IV thiamine infused over 30mins three times on days 1 and 2 of therapy
  • 250mg thiamine IV or intramuscularly on days 3- 5 of therapy

**Always give thiamine during the re-feeding period in a patient with alcoholism to prevent acute thiamine deficiency with lactic acidosis.**

Symptoms consistent with Wernicke-Korsakoff syndrome may persist for several months or may be permanent.  

Other symptoms of thiamine deficiency such as anorexia and irritability are expected to improve gradually.

The differential diagnosis for thiamine deficiency is broad given the number of nonspecific symptoms which may occur during the initial stages of this condition and the extensive range of cardiac and nervous dysfunction related to thiamine deficiency.

Conditions to consider:

  • Delirium
  • Depression
  • Folic acid deficiency
  • Hyperthyroidism
  • Cardiomyopathy secondary to other causes such as alcoholic or diabetic heart disease
  • Delusional disorder
  • Nerve entrapment syndromes
  • Other psychiatric disorders
  • Diabetic ketoacidosis

The overall prognosis for patients with thiamine deficiency is good as it is easily treatable and most signs and symptoms of the deficiency fully resolve with thiamine supplementation.

  Cardiac dysfunction seen in wet beriberi can be expected to improve within 24 hours of initiation of treatment. Symptoms of dry beriberi may improve or resolve.

  Unfortunately, once the deficiency has progressed to Korsakoff syndrome, the patient may show minimal improvement during initial treatment, and remaining symptoms may be permanent.

There are no known toxicities associated with thiamine repletion.

Some reports of anaphylaxis and bronchospasm with high-dose intravenous thiamine exist.

Enhancing healthcare team outcomes related to this condition is dependent on the cause.

  For deficiency related to excessive alcohol intake, steps to ensure the successful cessation of alcohol use may involve an interprofessional approach involving the medical team, social workers, community resources, and the use of inpatient or outpatient treatment strategies. In instances of inadequate dietary intake, nutritional counseling with a nutritionist or certified dietician may be in order.

Preventing this condition is as simple as ensuring total body levels of thiamine are adequate for metabolic processes. Education of patients who are at risk of deficiency is imperative, and any further counseling should point towards the underlying cause of the condition.

  For instance, patients who are undergoing alcohol detoxification should receive counseling on the signs, symptoms, and long-term effects of Korsakoff syndrome and an interprofessional team should be engaged to ensure the patient has adequate resources for detoxication and follow-up care. 

Patients need to be educated about eating a healthy diet, cease tobacco and abstain from alcohol. The dietitian should educate the patient on foods that are rich in thiamine. Only through a team approach can the morbidity of thiamine deficiency be reduced.

To access free multiple choice questions on this topic, click here.

1.Thiamine. Monograph. Altern Med Rev. 2003 Feb;8(1):59-62. [PubMed: 12611562]2.DiNicolantonio JJ, Liu J, O'Keefe JH. Thiamine and Cardiovascular Disease: A Literature Review. Prog Cardiovasc Dis. 2018 May – Jun;61(1):27-32. [PubMed: 29360523]3.Attaluri P, Castillo A, Edriss H, Nugent K. Thiamine Deficiency: An Important Consideration in Critically Ill Patients. Am. J. Med. Sci. 2018 Oct;356(4):382-390. [PubMed: 30146080]4.Wooley JA. Characteristics of thiamin and its relevance to the management of heart failure. Nutr Clin Pract. 2008 Oct-Nov;23(5):487-93. [PubMed: 18849553]5.Sriram K, Manzanares W, Joseph K. Thiamine in nutrition therapy. Nutr Clin Pract. 2012 Feb;27(1):41-50. [PubMed: 22223666]6.Whitfield KC, Bourassa MW, Adamolekun B, Bergeron G, Bettendorff L, Brown KH, Cox L, Fattal-Valevski A, Fischer PR, Frank EL, Hiffler L, Hlaing LM, Jefferds ME, Kapner H, Kounnavong S, Mousavi MPS, Roth DE, Tsaloglou MN, Wieringa F, Combs GF. Thiamine deficiency disorders: diagnosis, prevalence, and a roadmap for global control programs. Ann. N. Y. Acad. Sci. 2018 Oct;1430(1):3-43. [PMC free article: PMC6392124] [PubMed: 30151974]7.Zuccoli G, Pipitone N. Neuroimaging findings in acute Wernicke's encephalopathy: review of the literature. AJR Am J Roentgenol. 2009 Feb;192(2):501-8. [PubMed: 19155417]8.Osiezagha K, Ali S, Freeman C, Barker NC, Jabeen S, Maitra S, Olagbemiro Y, Richie W, Bailey RK. Thiamine deficiency and delirium. Innov Clin Neurosci. 2013 Apr;10(4):26-32. [PMC free article: PMC3659035] [PubMed: 23696956]


Understanding How Thiamine (Vitamin B1) Deficiency Causes Beriberi

Thiamine (Vitamin B1) Deficiency Symptoms, Causes & Treatment

 SilviaJansen / Getty Images

Running low on thiamine (a type of B vitamin) could put you at risk for a serious condition called beriberi. Since so many foods are rich in thiamine, beriberi is very rare in the United States. However, alcohol abuse and certain medical issues can increase your risk for thiamine deficiency.

Also known as vitamin B1, thiamine plays a key role in converting carbohydrates into energy. It’s also involved in the process of muscle contraction, as well as the transmission of nerve signals and the production of acids essential for proper digestion. While it’s mostly concentrated in your skeletal muscles, thiamine is also found in your brain, heart, liver, and kidneys.

When left untreated, beriberi can severely deplete your energy levels and result in life-threatening problems with your heart or nervous system.

There are two types of beriberi: wet beriberi (which affects the cardiovascular system) and dry beriberi (which affects the nervous system). If it goes unchecked, wet beriberi may cause injury to the heart’s muscle tissue. It’s also associated with congestive heart failure, in which the heart can’t pump enough blood to meet the body’s needs.

Dry beriberi injures the nerves and can lead to muscle strength loss and, eventually, paralysis. If the condition is detected and treated in its early stages, damage to the nervous system is usually reversible . Lack of early treatment may result in such complications as permanent memory loss.

Wernicke-Korsakoff syndrome is a type of brain disorder caused by a lack of thiamine. Typically, symptoms of Wernicke's disease are first to appear.

Symptoms include confusion, loss of muscle coordination, and changes in vision such as nystagmus (rapid, uncontrolled eye movements).

Korsakoff syndrome often develops later, with symptoms including memory loss, difficulty forming new memories, hallucinations, and making up stories (called confabulation).

Because drinking heavily interferes with your body’s ability to absorb and store thiamine, alcohol abuse is one of the main causes of beriberi today.

In very rare cases, beriberi occurs as a genetic disorder. For some individuals with this condition, the ability to absorb thiamine from foods gradually weakens with age.

Additionally, breastfed infants can develop beriberi when the mother’s body lacks sufficient thiamine.

Along with alcohol abuse, issues prolonged diarrhea and pregnancy-related vomiting are among the risk factors for beriberi.

In addition, undergoing dialysis, taking high doses of diuretics, and receiving bariatric surgery can all raise your risk of thiamine deficiency. People with hyperthyroidism, AIDS, or severe liver disease may also be more prone to this condition.

The most common symptoms of wet beriberi include:

  • Increased heart rate
  • Shortness of breath (including awakening at night short of breath)
  • Swelling of the lower legs

In cases where wet beriberi leads to congestive heart failure, individuals may experience the following symptoms:

  • Difficulty breathing accompanied by bulging neck veins 
  • Enlarged heart
  • Fluid in the lungs
  • Rapid heartbeat

For dry beriberi, symptoms typically include: 

  • Difficulty walking
  • Loss of feeling in the hands and feet
  • Loss of muscle function or paralysis of the lower legs
  • Mental confusion
  • Pain
  • Speech difficulties
  • Strange eye movements
  • Tingling
  • Vomiting

Following a balanced diet is your best bet for the prevention of beriberi. To get your fill of thiamine, load up on the following foods:

  • Beans and legumes
  • Dairy products (such as yogurt)
  • Eggs
  • Meat, poultry, and fish
  • Nuts and seeds
  • Thiamine-enriched breakfast cereals
  • Whole grains

The following vegetables are also high in thiamine:

  • Acorn squash
  • Asparagus 
  • Beet greens
  • Brussels sprouts
  • Spinach

It should be noted that a number of foods contain thiaminases, which are enzymes found to render thiamine inactive. These foods include:

  • Clams
  • Milled rice
  • Mussels
  • Shrimp

Limiting your intake of such foods may also aid in the prevention of beriberi.

Treatment of beriberi focuses on restoring the body’s thiamine levels. Some patients are treated with thiamine supplements, while others receive thiamine injections.

In most cases, undergoing treatment for beriberi alleviates symptoms and reverses damage to the heart or nervous system.

Failure to treat beriberi (and Wernicke-Korsakoff syndrome) can result in permanent damage to the heart and/or nerves, as well as coma, psychosis, and even death.

If you’re a heavy drinker, taking vitamin B supplements isn’t recommended as a prevention strategy for beriberi. According to the Substance Abuse and Mental Health Services Administration 404, heavy alcohol use is defined as binge drinking (i.e., consuming about four drinks for women and five drinks for men) on five or more days in the past month.

If you’re experiencing any signs of thiamine deficiency, consult your physician as soon as possible.

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  1. Lee HS, Lee SA, Shin HS, et al. A case of cardiac beriberi: a forgotten but memorable disease. Korean Circ J. 2013;43(8):569-72. doi:10.4070/kcj.2013.43.8.569

  2. Shible AA, Ramadurai D, Gergen D, Reynolds PM. Dry beriberi due to thiamine deficiency associated with peripheral neuropathy and wernicke's encephalopathy mimicking guillain-barré syndrome: a case report and review of the literature. Am J Case Rep. 2019;20:330-334. doi:10.12659/AJCR.914051

  3. Bravatà V, Minafra L, Callari G, Gelfi C, Edoardo grimaldi LM. Analysis of thiamine transporter genes in sporadic beriberi. Nutrition. 2014;30(4):485-8. doi:10.1016/j.nut.2013.10.008

Additional Reading


What is Thiamine (Vitamin B1)?

Thiamine (Vitamin B1) Deficiency Symptoms, Causes & Treatment

Vitamin B1, also called thiamine, is a B complex vitamin. It is found in many foods and is vitally important to keeping a body operating properly. 

“Thiamine is involved in many body functions including the nervous system, heart and muscles,” said Dr. Sherry Ross, gynecologist and Women’s Health Expert at Providence Saint John’s Health Center in Santa Monica, California. “It is also important in the flow of electrolytes in and nerve and muscle cells, enzymatic processes and carbohydrate metabolism.”

According to the University of Maryland Medical Center (UMM), thiamine was named B1 because it was the first B complex vitamin to be discovered. According to the Mayo Clinic, it was also one of the first vitamins of any kind ever be classified. 

B1 sources

There are many natural ways to add thiamine-rich foods to an everyday diet. Food sources of thiamine include beef, liver, dried milk, nuts, oats, oranges, pork, eggs, seeds, legumes, peas and yeast.  Foods are also fortified with thiamine. Some foods that are often fortified with B1 are rice, pasta, breads, cereals and flour. 

Health benefits of thiamine

Thiamine is used to treat people who have heart disease, metabolic disorders, aging, canker sores, cataracts, glaucoma and motion sickness. There are many studies that seem to back up some of these uses.

For example, research published by the Vietnamese American Medical Research Foundation found thiamine might improve the cognitive function of patients with Alzheimer's disease.

This vitamin is important for a wide range of brain functions and ailments in others, as well.

According to the UMM, thiamine is sometimes called an “anti-stress” vitamin. Research has found that B1 may strengthen the immune system and improve the body's ability to control mood and physiological impairments due to stress.

“Thiamine is also used for maintaining a positive mental attitude, preventing memory loss, enhancing learning abilities, fighting stress and increasing energy,” Ross told Live Science. Thiamine injections are also given to patients who have a memory disorder called Wernicke’s encephalopathy, Ross added. 

B1 may also be good for treating other impairments. According to the Milton S. Hershey Medical Center, many studies have also concluded that B1, along with other vitamins, may prevent cataracts.

A study by the Laboratory of Pharmacotherapy at the Osaka University of Pharmaceutical Sciences in Takatsuki, Japan found that thiamine has a potential to prevent obesity and metabolic disorders in rats.

 Other researchers believe that vitamin B plays a part in the body's metabolism and may be interregnal to the treatment of metabolic disorders. 


The recommended daily allowance (RDA) for B1 varies, depending on age and gender. Here are the RDA levels of B1 according to the U.S. National Library of Medicine: 

  • Males who are 14 and older should consume 1.2 milligrams per day (mg/day).
  • Females who are 14 to 18 years old should consume 1.0 mg/day.
  • Females who are 19 and older should consume 1.1 mg/day, though women who are pregnant or breastfeeding may need more and should consult her doctor.

Typically, most people can get their daily dose of B1 from eating healthy foods. Some may opt to take a multivitamin or a supplement to ensure that the RDA is met. Many vitamin supplements can cause overdose and medical problems, but B1 is fairly safe in this respect.

“Because they are water soluble it is less ly you will overdose on them as other vitamins,” said Dr. Kristine Arthur, internist at Orange Coast Memorial Medical Center in Fountain Valley, California.

Ross agrees and stated that thiamine is considered safe at high doses and is relatively nontoxic.

B1 deficiency

Though rare in developed countries the United States, deficiencies in B1 can create serious medical problems. Severe deficiency of thiamine causes complications involving the nervous system, brain, muscles, heart and gastrointestinal system,” said Ross.

“If you are deficient you can develop specific disorders such as Beriberi and Wernicke- Korsakoff syndrome,” said Arthur.

Beriberi can cause abnormal nerve function, heart failure and swelling in the legs, while Wernicke Korsakoff syndrome can cause memory loss, confusion and difficulty with balance. These problems are most common in alcoholics.

Drinking too much alcohol makes it harder for the body to absorb and store thiamine, according to the National Library of Medicine. In many cases, alcoholism treatment includes B1 therapy. 

Beriberi can also be passed down through genes. The elderly are also susceptible to thiamine deficiency. This is because their bodies have a harder time absorbing the vitamin. 

The use of diuretics is another cause for B1 deficiency, according to Oregon State University. Since B1 is water soluble and is not stored in the body, diuretics, which primary use is to flush water from the body, also flushes away vitamins thiamine. 

Symptoms of vitamin B1 deficiency

The symptoms of B1 deficiency are many and typically are related to the nervous, muscular and gastrointestinal systems.

According to a review published by the journal Congestive Heart Failure, symptoms include depression, emotional instability, uncooperative behavior, fearfulness, agitation, weakness, dizziness, insomnia, memory loss, pain sensitivity, peripheral neuropathy, sonophobia, backache, muscular atrophy, myalgia, nausea, vomiting and constipation.

Additional resources