Beriberi and Wernicke Encephalopathy: Thiamin Deficiency, Alcohol Use and Treatment
Beriberi and Wernicke encephalopathy are serious thiamin (vitamin B1) deficiency conditions linked to alcohol use and poor absorption: signs, risk groups and why care is urgent.
Content last updated . This page has not been medically reviewed.
Urgent medical care note
Wernicke encephalopathy is treated as a medical emergency. The US National Institute on Alcohol Abuse and Alcoholism (NIAAA) says early symptoms of Wernicke's disease can be reversed if detected and treated promptly and completely, and that it should be considered a medical emergency. [1] MedlinePlus says to contact your health care provider or go to the emergency room if you have symptoms of Wernicke-Korsakoff syndrome. [2] In the US, call 911 for an emergency. Confusion, loss of muscle coordination, unusual eye movements or double vision are symptoms MedlinePlus lists for Wernicke encephalopathy, and they are reasons to get urgent help, not to wait. [2]Alcohol withdrawal can also be dangerous. NIAAA says that when someone who has been drinking heavily for a long time suddenly stops, the body can go into a painful or even potentially life-threatening withdrawal, and people should seek medical help to plan a safe recovery. [1] If you are in distress, the 988 Suicide & Crisis Lifeline (US) is a number to use.
What these conditions are
Thiamin (also spelled thiamine, vitamin B1) helps cells change carbohydrates into energy and plays a role in muscle contraction and nerve signals. [3] Beriberi is a disease in which the body does not have enough thiamine. [4] MedlinePlus describes two major types: wet beriberi, which affects the cardiovascular system, and dry beriberi and Wernicke-Korsakoff syndrome, which affect the nervous system. [4] Wernicke encephalopathy and Korsakoff syndrome are different conditions that often occur together, both caused by brain damage from a lack of vitamin B1. [2] For the vitamin itself see Thiamin (Vitamin B1).Signs and symptoms
| Condition | Symptoms listed by the source |
|---|---|
| Dry beriberi | Difficulty walking, loss of feeling in hands and feet, loss of muscle function or paralysis of the lower legs, mental confusion, pain, speech difficulties, strange eye movements, tingling, vomiting [4] |
| Wet beriberi | Waking at night short of breath, increased heart rate, shortness of breath with activity, swelling of the lower legs [4] |
| Wernicke encephalopathy | Confusion that can progress to coma, loss of muscle coordination, abnormal eye movements, double vision, drooping eyelids [2] |
| Korsakoff syndrome | Inability to form new memories, severe memory loss, making up stories, seeing or hearing things that are not there [2] |
These symptoms have many possible causes. They do not prove thiamin deficiency, and a clinician must assess them.
Testing
MedlinePlus lists blood tests for thiamine and urine tests for thiamine as tests that may be done for beriberi. [4] For Wernicke-Korsakoff it lists serum vitamin B1 and transketolase activity in red blood cells, which is reduced in thiamine deficiency, and notes a brain MRI may show changes but is usually not needed if the syndrome is suspected, because treatment should start immediately. [2] NIAAA says the syndrome is diagnosed clinically from history and symptoms. [1] This is why a person with symptoms should not wait for a test result before getting help. See Vitamin Deficiency Testing.Treatment is clinician-led
MedlinePlus says the goal in beriberi is to replace missing thiamine, given by injection or by mouth, sometimes with other vitamins. [4] For Wernicke-Korsakoff, vitamin B1 is usually given by injection into a vein or muscle as soon as possible. [2] NIAAA says doctors treat Wernicke's disease with intravenous vitamin B1 and glucose. [1] A 2014 clinical review notes that although thiamine is the cornerstone of treatment, there are no universally accepted guidelines on its optimal dose, route, frequency or duration. [5] For that reason we give no treatment amounts here.Outlook. MedlinePlus says untreated beriberi can be fatal, symptoms usually improve quickly with treatment, and heart damage is usually reversible unless acute heart failure has already occurred. [4] Nervous-system damage is reversible if caught early. Otherwise some symptoms, such as memory loss or confusion, may remain. [4] Thiamin often does not improve the memory and intellect loss of Korsakoff syndrome, and stopping alcohol can prevent more loss of brain function. [2]
Official intake references
| Group and country | Reference | Source and year |
|---|---|---|
| Men 14 and older, US (RDA) | 1.2 mg a day | MedlinePlus citing US Dietary Reference Intakes, 2025 [3] |
| Women 19 and older, US (RDA) | 1.1 mg a day; 1.4 mg in pregnancy and lactation | MedlinePlus, 2025 [3] |
| Infants 0 to 6 months / 7 to 12 months, US (AI) | 0.2 mg / 0.3 mg a day | MedlinePlus, 2025 [3] |
| Adults 19 to 64, UK | 1 mg a day for men, 0.8 mg for women | NHS, 2020 [6] |
MedlinePlus says there is no known poisoning linked to excessive thiamin intake. [3] The NHS says there is not enough evidence on the effects of high-dose thiamin supplements, and that 100 mg or less a day is unlikely to cause harm. [6] The NHS notes that thiamin cannot be stored in the body, so it is needed in the diet every day. [6] MedlinePlus lists enriched, fortified and whole grain products, pork and beef, eggs, legumes, nuts and seeds among food sources. [3] For alcohol and the other vitamins it affects, see Vitamins and Alcohol.
Frequently asked questions
What is the difference between beriberi and Wernicke-Korsakoff syndrome?
Both come from thiamine deficiency. MedlinePlus groups dry beriberi and Wernicke-Korsakoff syndrome as nervous-system forms, and wet beriberi as affecting the heart and circulation. [4]
Is Wernicke encephalopathy an emergency?
Yes. NIAAA says it should be considered a medical emergency, because early symptoms can be reversed with prompt treatment. [1]
Can you get beriberi without drinking alcohol?
Yes, though less often. MedlinePlus lists absorption problems, certain medical treatments, infant feeding problems and rare genetic causes. [4]
Will a thiamin supplement prevent it?
Not reliably. MedlinePlus says supplements and a good diet may reduce the chance in heavy drinkers but the risk is not eliminated. [2]
Can thiamin deficiency be checked with a blood test?
Tests exist, such as serum vitamin B1 and red-cell transketolase, but treatment should not wait for results when Wernicke-Korsakoff is suspected. [2]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Who is at risk
- Alcohol use disorder. MedlinePlus says beriberi today occurs mostly in people who drink too much alcohol, because excess alcohol makes it harder to absorb and store vitamin B1. [4] NIAAA says poor nutrition in severe alcohol use disorder reduces the gut's ability to absorb thiamine. [1]
- Absorption problems and surgery. Lack of vitamin B1 is also common in people whose bodies do not absorb food properly, which can occur with a chronic illness or after weight-loss (metabolic bariatric) surgery. [2] See Vitamins After Bariatric Surgery and Malabsorption, Celiac Disease, IBD and Vitamin Deficiency.
- Other conditions. MedlinePlus lists HIV/AIDS, chemotherapy or cancers that have spread, extreme nausea and vomiting during pregnancy, heart failure treated with long-term diuretics, long periods of intravenous nutrition without thiamine, long-term dialysis, and very high thyroid hormone levels. [2] Dialysis and high doses of diuretics are also listed as treatments that can raise beriberi risk. [4]
- Infants. Beriberi can occur in infants who are breastfed by a mother lacking thiamine or fed unusual formulas without enough thiamine. [4]
- Genetics. In rare cases beriberi can be genetic, and MedlinePlus says the diagnosis is often missed in people who do not drink alcohol. [4]
NIAAA notes that Wernicke-Korsakoff syndrome may remain undiagnosed in approximately 80 percent of patients, according to researchers' estimates. [1]
Prevention and safety points
- MedlinePlus says eating a diet rich in vitamins prevents beriberi, that people who drink heavily should try to cut down or quit, and that for a heavy drinker who cannot or will not quit, thiamine supplements and a good diet may reduce the chance of Wernicke-Korsakoff syndrome but do not eliminate the risk. [4][2] Do not rely on a supplement alone, and do not stop drinking suddenly without medical advice.
- Pregnancy: extreme vomiting in pregnancy is listed as a cause of thiamine deficiency, so persistent vomiting should be reported to the care team. [2] See Pregnancy & Breastfeeding.
- Kidney, liver and heart conditions: dialysis, diuretics and heavy alcohol use affect risk, and liver enzymes may be high with long-term heavy drinking. [2][4] Never change a prescribed medicine without asking your prescriber; see medication interactions and Vitamins and Kidney or Liver Disease.
- Surgery, infants and product quality: Proper evidence not found in the sources we read for supplement rules specific to these topics; ask a clinician or pharmacist. See Quality Testing and Certifications.
References
- National Institute on Alcohol Abuse and Alcoholism (NIAAA, US). Wernicke-Korsakoff Syndrome. Updated December 2025. Read 2026-10-23.
- MedlinePlus Medical Encyclopedia (US National Library of Medicine). Wernicke-Korsakoff syndrome. Review date 1/27/2026. Read 2026-10-23.
- MedlinePlus Medical Encyclopedia (US National Library of Medicine). Thiamin. Review date 1/21/2025. Read 2026-10-23.
- MedlinePlus Medical Encyclopedia (US National Library of Medicine). Beriberi. Review date 7/23/2024. Read 2026-10-23.
- Latt N, Dore G. Thiamine in the treatment of Wernicke encephalopathy in patients with alcohol use disorders. Intern Med J. 2014;44(9):911-915. PMID 25201422. Abstract read 2026-10-23.
- NHS (UK). Vitamins and minerals: B vitamins and folic acid. Page last reviewed 3 August 2020. Read 2026-10-23.