Wernicke Encephalopathy After Weight-Loss Drugs and Gut Surgery

Table of Contents

1. Thiamine Stores Last Only Weeks
2. Reports After Semaglutide and Tirzepatide
3. Reports After Bariatric and Other Gut Surgery
4. Which Procedures Appear Most in the Reports
5. Signs Hospitals Treat as Urgent
6. How Often Thiamine Is Measured and What Studies Found
7. Thiamine Treatment Reported and the Outcomes
8. What Guidelines State
9. What Is Not Known
10. Key Research Papers
11. Connections
12. Featured Videos

Thiamine Stores Last Only Weeks

Thiamine is a water-soluble vitamin the body uses to turn food into energy. A 2021 study of bariatric patients describes the body's stores as limited, and the full text of a 2026 review of semaglutide cases states that they may be exhausted within weeks when intake falls or demand rises. Unlike a vitamin stored for years, thiamine leaves little margin for a long stretch of poor eating.

The reports point to several routes to an empty store, and one person can have more than one:

• Eating very little. Semaglutide, tirzepatide and their relatives work through appetite suppression, reduced energy intake and stomach and bowel effects. A 2026 review lists reduced food intake, lower dietary variety, delayed stomach emptying and rapid weight loss as the pathways that may lower vitamin and mineral status. Weight-loss operations also limit how much a person can eat.
• Vomiting. Vomiting removes food and any vitamin pill taken with it. In a 2008 systematic review of cases after bariatric surgery, frequent vomiting was a risk factor in 76 of 84 cases (90%) and had lasted a median of 21 days by the time of hospital admission.
• Bypassing part of the gut. The full text of a 2026 systematic review describes the first part of the small intestine (the duodenum and proximal jejunum) as a key site of thiamine absorption, so operations that route food past it carry extra concern. Sleeve operations do not bypass this stretch, yet they still appear in the reports, and a 2018 review traces this largely to vomiting.
• Starting low. Several studies found low thiamine in people with obesity before any operation or drug (see the measurement section). A 2005 paper notes that people whose carbohydrate comes mainly from refined sugars and milled rice are at greater risk, because fats, oils and refined sugars contain no thiamine.
• A sudden sugar load. Burning carbohydrate uses thiamine. Intravenous glucose given without thiamine was recorded as a risk factor in 15 of the 84 cases (18%) in the 2008 review. The glucose question is covered on the Wernicke-Korsakoff page, including its low-blood-sugar exception.

Fast weight loss has also been reported as the setting without either a drug or an operation. A 2025 case series describes three young men with thiamine deficiency affecting the eyes and optic nerve after rapid weight loss through strenuous exercise.

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Reports After Semaglutide and Tirzepatide

Semaglutide belongs to the glucagon-like peptide-1 (GLP-1) receptor agonists. Tirzepatide acts on the same receptor and a second gut-hormone receptor. A separate page covers what these drugs do and how much weight people lost in the trials. The full text of a 2026 review states that large trials of semaglutide did not report Wernicke encephalopathy as an adverse outcome. The evidence comes from individual cases and from safety databases:

• A 2026 United States database study and literature review identified 15 cases: 13 from the Food and Drug Administration adverse event database, 1 from published literature and 1 from the authors' own hospital. Semaglutide accounted for 8 and tirzepatide for 6, and 14 were reported in 2023 and 2024. Thirteen patients had weight loss, vomiting, loss of appetite or malnutrition. Classic symptoms were reported in 11 patients, the full three-part picture in only 2. Long-term nerve or brain problems were noted in 7 of the 11 patients with follow-up data.
• The same study's reporting comparison. Reports of Wernicke encephalopathy made up a larger share of reports for these drugs than for other medications, with a reporting odds ratio of 2.35 (95% confidence interval 1.38 to 4.01). This compares shares of reports. It is not a rate among people taking the drugs.
• A 2025 analysis described a 49-year-old woman on semaglutide for obesity with repeated vomiting and reduced food intake, plus 18 other cases from the literature and the World Health Organization safety database. Nausea, vomiting or reduced intake was described in 68% of cases. Weight loss ranged from 3.5 to 13.3 kg per month over 3 to 6 months. Wernicke encephalopathy was reported disproportionately with semaglutide, tirzepatide and the whole drug group, and the authors called this a safety signal.
• A 2026 systematic review of case reports found six cases of semaglutide prescribed for obesity. All six patients had prolonged stomach and bowel symptoms and substantial weight loss before the nerve signs began. Altered mental state and eye movement problems were common. Outcomes were poor in several, including Korsakoff syndrome (lasting memory loss) or death.
• A 2024 case report describes a 37-year-old man on semaglutide who came to an emergency room with trouble swallowing, slurred speech, difficulty finding words and restricted eye movements.
• A 2025 case report describes a 37-year-old woman prescribed semaglutide for diabetes and weight loss. After three months of marked weight loss she developed numbness and weakness in both legs and blurred vision. She was first diagnosed with vitamin B12 deficiency and worsened despite supplements, then developed acute confusion. Tests found thiamine deficiency. Her doctors favored non-alcoholic Wernicke encephalopathy together with a nerve condition linked to rapid blood-sugar control.
• A 2026 case report describes a 50-year-old man with obesity and chronic alcohol use disorder who developed Korsakoff syndrome within weeks of starting tirzepatide, during rapid weight loss. Alcohol is itself a leading cause, so this case cannot separate the drug from the drinking. The authors raise concern about vulnerable people, particularly those with chronic alcohol use disorder.

The timing in these reports runs from within weeks of starting (the 2026 tirzepatide case) to about three months (the 2025 semaglutide case), with 3 to 6 months of weight loss described in the 2025 analysis. These counts overlap, because reviews and databases can include the same patient, so they cannot simply be added together.

A 2026 narrative review places these cases in context. It states that most vitamin and mineral abnormalities reported so far on these drugs are subclinical or indirect, that thiamine is a context-dependent concern, and that clinically meaningful consequences may occur in susceptible people, including those with earlier bariatric surgery, gut disorders, a poor diet to begin with, older age or prolonged nausea and vomiting.

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Reports After Bariatric and Other Gut Surgery

Bariatric surgery means an operation done to produce weight loss. The record here is far larger and older than the drug record.

• A 2008 systematic review found 104 reported cases and included 84. Hospital admission for Wernicke encephalopathy came within 6 months of surgery in 79 cases (94%). Brain magnetic resonance imaging (MRI) showed the characteristic lesions in 14 of 30 cases (47%). The author linked the rise in United States bariatric surgery, an estimated 205,000 procedures in 2007, to a rise in reported cases.
• A 2018 review gathered 118 cases. Patients were young, with a median age of 33 years. Vomiting was described in 87.3%, an unsteady walk in 84.7%, altered mental state in 76.3% and eye movement disorder in 73.7%.
• A 2026 systematic review looked beyond weight-loss surgery, at non-alcoholic adults after gut procedures in studies from 2000 to 2025: 13 studies involving 1,036 patients. Its full text notes that not all of those patients developed the condition, since many studies covered whole surgical groups. Bariatric, cancer and emergency gut operations were all associated with Wernicke encephalopathy, and vomiting was the most common trigger.
• A 2026 systematic review of nerve complications after bariatric surgery covered 12 studies and over 5,000 patients. Any nerve complication was reported in 1.4% to 16%, most often peripheral nerve damage. Wernicke encephalopathy occurred less often but was considerably more severe. Thiamine deficiency was the main cause named, and onset ranged from days to several years after surgery.

Teenagers and young adults appear in the reports too:

• A 2024 hospital chart review of people aged 10 to 25 years covered 30 patients with thiamine deficiency after surgery. Of 1,575 operated at that hospital, 7 later had the deficiency (0.45 per 100), and 23 more had been operated elsewhere. Time from surgery to admission averaged 4.97 months and weight lost averaged 33.68 kg. Poor oral intake was recorded in 90%, nausea and vomiting in 80% and not taking multivitamins in 71%. Seven had the full three-part picture of Wernicke encephalopathy and 16 a mix of Wernicke encephalopathy and dry beriberi.
• A 2024 case series describes three women after sleeve surgery with no immediate complications, then heavy vomiting from about two weeks later, followed by confusion, eye movement problems and weakness over the next thirty days.
• A 2024 report describes three adolescents aged 15.5 to 17 years with worsening leg pain and weakness 2 to 3 months after a sleeve operation or the narrowing of a gastric band. All three were not taking their vitamin and mineral supplements.

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Which Procedures Appear Most in the Reports

The operations differ in what they change. A gastric band and a sleeve gastrectomy make the stomach smaller. A Roux-en-Y gastric bypass makes a small stomach pouch and routes food past the first part of the small intestine. Biliopancreatic diversion with duodenal switch bypasses a longer stretch of intestine.

A 2023 literature review covering 1985 to 2023 gave these overall figures per 100,000 cases:

• Sleeve gastrectomy: 1.06
• Gastric band: 1.16
• Roux-en-Y gastric bypass: 4.29
• Biliopancreatic diversion with duodenal switch: 8.92

These figures come from a review of the literature, not a register that followed every patient, so they depend on which cases reached print. The same review notes that the most common procedure has shifted over the years, and case counts shift with it:

• In the 2018 review, gastric bypass made up 52% of the 118 cases, and the full text notes that sleeve reports were more recent, possibly because sleeve surgery has grown more popular.
• In the 2024 review of young patients, 96.7% had sleeve gastrectomy.
• A 2005 paper states that most cases reported up to that time followed Roux-en-Y gastric bypass, with fewer after biliopancreatic diversion, vertical banded gastroplasty or duodenal switch.

A large share of cases therefore does not by itself mean a high risk per operation. A procedure done very often can lead the case count while having a lower figure per 100,000. The 2018 review's full text states that all bariatric procedures can lead to deficiency, and that newer operations with no bypass still produce the main risk factor, vomiting.

Weight-loss surgery is not the only setting. In the 2026 review of gut procedures, cancer and emergency operations were on the list, and severe vomiting in pregnancy and refeeding after starvation are described on their own pages.

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Signs Hospitals Treat as Urgent

Taken from the reports above, these are the findings that appear in the setting of weeks of vomiting, very low intake or fast weight loss:

• Confusion, an altered mental state or new memory trouble
• Double vision, blurred vision, jerking eyes or an eye that will not move fully
• An unsteady, staggering walk
• Numbness, pain or weakness in the legs
• Trouble swallowing or slurred speech, as in one 2024 case
• Vomiting that does not stop. The British guideline's full text states that prolonged vomiting or trouble swallowing after bariatric surgery is not normal and is always investigated.

Wernicke encephalopathy is classically described by three signs: confusion, an unsteady walk and abnormal eye movements. The full set is the exception. It appeared in only 2 of 15 patients in the 2026 database study and in a minority of patients in the 2026 review of gut procedures, where most patients presented with atypical features such as memory and thinking problems and nerve damage in the limbs.

The reports also show how easily the condition is mistaken for something else:

• The 2025 semaglutide patient was first treated for vitamin B12 deficiency.
• An 18-year-old woman in a 2026 report, 10 weeks after sleeve surgery and 30 kg lighter in three months, lost independent walking. Her illness was first attributed to a functional disorder. Thiamine was never measured, so the cause stayed unresolved, and she did not have vomiting.
• The 2026 tirzepatide patient had a first brain magnetic resonance imaging scan read as unremarkable.
• The full text of the 2026 semaglutide review notes that early thiamine deficiency symptoms (tiredness, weakness, poor appetite, stomach discomfort) overlap with the expected side effects of the drug itself.

Hospital practice as stated in guidelines does not wait for proof. The European guideline indicates thiamine for suspected as well as manifest disease, and states that injected thiamine is given to all at-risk people admitted to an emergency room. Thiamine deficiency can also reach beyond the brain: the British guideline's full text lists heart failure with a fast pulse and breathing symptoms, which is wet beriberi.

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How Often Thiamine Is Measured and What Studies Found

Measurement appears to be patchy, and this page holds no study giving a figure for how often thiamine is actually tested in people on these drugs. What the sources state:

• The 2016 American surgical nutrition guideline states that preoperative vitamin screening has not been the norm in most weight-loss surgery practices, and that monitoring at follow-up is decreasing while deficiencies are increasing.
• The 2020 British guideline's full text states that few studies measure thiamine before surgery.
• The 2026 review of gut procedures reports in its full text that only a limited number of its studies assessed blood thiamine.
• The 2026 semaglutide review reports in its full text that thiamine testing and nutritional status were inconsistently reported across its cases.
• A 2025 review states that bariatric surgery guidelines set out structured nutritional monitoring while no equivalent framework exists for these drugs.

Where thiamine was measured, the results vary widely:

• Before bariatric surgery, pooled. A 2024 meta-analysis of 41 studies found thiamine deficiency in 7% of candidates (95% confidence interval 4% to 12%).
• After bariatric surgery, pooled. The same analysis found 19% at 3 months (95% confidence interval 0% to 68%), 9% at 6 months (3% to 17%) and 6% at 1 year (3% to 9%). The very wide range at 3 months shows how uncertain the early figure is. In pregnancies after bariatric surgery it found 12% in the first trimester, 8% in the second and 10% in the third.
• After sleeve gastrectomy. A 2018 United States chart review found deficiency in 27 of 105 patients (25.7%) within a year, using a cutoff under 78 nM. Nausea (odds ratio 3.81), vomiting (odds ratio 3.49), higher starting body mass index (odds ratio 1.13) and African American race (odds ratio 3.9) were independent risk factors. Reported vitamin compliance did not differ significantly between those with and without deficiency (70.4% and 84.6%, P = .10).
• Before surgery, single centers. A 2021 study of 346 patients found 3.5% under its lower limit of 70 nM, and a further 14% at risk under 100 nM. A 2005 study found low levels in 47 of 303 patients (15.5%). The 2018 sleeve authors quote 1.8% from their own earlier work.
• Obesity without surgery. A 2017 study of 400 people in a preoperative clinic, excluding earlier surgery and heavy drinking, diagnosed clinical thiamine deficiency in 66 (16.5%), using symptoms plus either a low blood level or a response to thiamine. A 2025 study of 146 United States veterans in a weight clinic found deficiency in 32.2%. Recent weight loss was linked to higher odds in that study, but not significantly (odds ratio 2.04, 95% confidence interval 0.79 to 5.27).
• On these drugs. A 2025 insurance claims analysis of 461,382 adults newly prescribed these drugs, from July 2017 to December 2021, found any nutritional deficiency diagnosis in 12.7% within 6 months and 22.4% within 12 months, led by vitamin D (7.5% and 13.6%). Most had type 2 diabetes (80.5%). These are recorded diagnoses, not blood tests of everyone. A 2025 narrative review states that vitamin D was most common in such data, followed by thiamine and other B vitamins.

The studies differ in the test, the cutoff, the clinic and the patients, so their figures cannot be lined up directly. The test itself has limits: a 2021 clinical review describes an absence of specific diagnostic tests for thiamine deficiency disorders, and the full text of the 2026 gut-procedure review states that serum thiamine can look normal in people with symptoms, while whole blood levels can support the diagnosis.

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Thiamine Treatment Reported and the Outcomes

The treatment most reports describe is thiamine given by vein or into a muscle. The regimens themselves, and why there is no single proven dose, are set out on the Wernicke-Korsakoff page. What these particular groups of patients received varied:

• The 2026 review of gut procedures found that early intravenous thiamine was associated with favorable outcomes, with dosing protocols that varied considerably between studies.
• The 2018 review of 118 bariatric cases called treatment often insufficient and gives a figure of 77.2% for low-dose injected thiamine among the cases it could assess.
• The 2026 semaglutide review's full text reports that treatment details were fully described in only some cases and that several patients received doses below the level it defined as adequate.

Outcomes run from complete recovery to death:

• Full recovery. A 23-year-old woman with double vision two months after gastric bypass and a thiamine level of 20 ng/mL, reported as deficient, received thiamine 600 mg a day with folic acid 5 mg a day and cyanocobalamin 1 mg a day, and her symptoms resolved completely (2026 report). Her picture was an isolated eye nerve palsy.
• Marked improvement. The three adolescents in the 2024 report received intravenous thiamine and oral multivitamins, and their symptoms improved considerably.
• Mixed. In the 2024 review of young patients, half achieved complete resolution, while 47% had residual weakness and 40% persistent sensory symptoms. No one died.
• Lasting harm. In the 2008 review, recovery was incomplete in 41 of 84 cases (49%), with memory and walking problems frequent. In the 2024 sleeve series, all three women had memory and thinking problems and nerve damage one year on, and two met the criteria for Korsakoff syndrome. The 2026 tirzepatide patient's memory problems persisted despite intravenous thiamine. In the 2026 database study, 7 of 11 patients with follow-up had long-term nerve or brain problems.
• Death. The 2026 semaglutide review counted death among its outcomes. Death rates in the 2026 review of gut procedures ranged from 0.3% in bariatric groups to 40% in cancer patients. Its full text attributes the gap to patient age, how malnourished patients were and likely later recognition, not to dose.

A 2021 clinical review states that even severe cases can improve within hours or days of thiamine, while neurological involvement may take higher doses and longer recovery. None of these groups were randomized, so they cannot show which dose or timing is best.

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What Guidelines State

• European Federation of Neurological Societies, 2010. Wernicke encephalopathy is to be suspected in all clinical conditions that could lead to thiamine deficiency. Diagnosis takes account of different signs in people who drink and those who do not. Total blood thiamine is measured immediately before giving it. Treatment of suspected or manifest disease is 200 mg three times daily, preferably intravenously, before any carbohydrate (graded Level C). After bariatric surgery it recommends follow-up of thiamine status for at least 6 months (Level B) and parenteral thiamine supplementation (a good practice point). It also rates the overall safety of thiamine as very good.
• British Obesity and Metabolic Surgery Society, 2020 update. The full text states that the working group did not find strong evidence for routine checking of thiamine levels before surgery. It lists prolonged vomiting, rapid weight loss, poor diet, alcohol abuse, swelling or nerve symptoms as risk factors, and states that treatment begins immediately when deficiency is suspected, without waiting for test results. A complete multivitamin and mineral supplement containing thiamine is its routine after all bariatric procedures, and it notes that this may not be enough. It states that glucose is not given by mouth or vein to people at risk, as it can set off the syndrome, and that hospital admission and injected thiamine merit consideration when deficiency is suspected.
• American Society for Metabolic and Bariatric Surgery, 2016 update. It covers screening, preventive supplementation and repletion for vitamin B1 among other nutrients, with 92 recommendations graded A to D. The British guideline's full text notes that it could not find sufficient evidence for the higher routine thiamine amounts named in this American document, while accepting that more research is needed. So the guideline groups differ on routine supplement amounts.
• The 2025 joint advisory on nutrition with these drugs, from four American lifestyle medicine, nutrition and obesity societies, names nutritional deficiencies from calorie reduction as a challenge and lists preventing nutrient deficiencies as a priority. A text search of its open full text finds no mention of thiamine.

Paper authors add statements of their own, which are not guidelines. The 2026 semaglutide review states that clinicians are to stay vigilant for thiamine deficiency in patients with persistent stomach and bowel intolerance or rapid weight loss, and calls early injected thiamine essential. The 2026 tirzepatide case report raises nutritional assessment and thiamine supplementation when starting treatment. The 2026 review of gut procedures calls for strong consideration of preventive thiamine in high-risk patients. A 2026 narrative review proposes individual assessment and targeted laboratory monitoring for high-risk patients.

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What Is Not Known

• How often this happens on these drugs. A case report has no denominator: it describes one person and says nothing about how many others took the same drug with no such event. Safety databases rely on voluntary reports, and a reporting odds ratio compares shares of reports. Neither gives a rate, and the authors of the 2026 narrative review state that prospective studies are needed to define incidence.
• Whether the drug itself is the cause. The reports describe an association in time. The path the authors propose runs through vomiting, low intake and weight loss, and none of the sources read for this page describes a direct effect of the drug on thiamine. Alcohol use and earlier bariatric surgery can sit in the same patient: the 2026 tirzepatide patient had chronic alcohol use disorder, and the 2026 semaglutide review's full text notes that alcohol use and earlier surgery were not consistently reported and that most of its patients had other illnesses.
• How the risk compares with other fast weight loss. Reports from surgery, exercise and drugs share similar stories, but no study here compares them head to head.
• Who on these drugs is most at risk. The risk groups named in reviews rest on small numbers and, in part, on extrapolation from surgery. The 2025 analysis notes that the higher doses recently approved for obesity still need further assessment, and the large claims analysis ended in December 2021.
• The true rate after each operation. The per-100,000 figures rest on published cases, and the 2008 review concluded that the number of cases was substantially higher than previously reported. The full text of the 2026 review of gut procedures describes the evidence as mainly retrospective and case series, and calls for prospective data.
• Whether preventive thiamine works in these settings, and at what dose. The sources reviewed for this page describe no randomized trial of preventive thiamine in people on these drugs or after these operations. The 2026 semaglutide review's full text says prospective studies are needed for this.
• The best test. Blood tests, cutoffs and clinical definitions differ between studies, which is one reason the figures vary from 1.8% to 32.2% among people with obesity.

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Key Research Papers

1. Bidesie J, Oudman E. Wernicke's Encephalopathy Following Semaglutide Treatment for Obesity: A Systematic PRISMA Review of Case-Based Evidence. Obesity (Silver Spring). 2026;34 Suppl 2(Suppl 2):64-69. PubMed PMID: 42399213
2. Lev D, Leibowitz A, Lang A, Shlomai G, Twig G, Eden-Friedman Y, Engel T, Cukierman-Yaffe T, Dankner R, Gerstein HC, Goldman A. Glucagon-like peptide-1 receptor agonists and Wernicke encephalopathy: A pharmacovigilance study and literature review. Clin Nutr. 2026;57:106571. PubMed PMID: 41534460
3. Gras C, De Wit V, Oussedik N, Daclin S, Bourdin V, Callot D, Chegrani G, Rives-Lange C, Chouchana L. Semaglutide-induced Wernicke encephalopathy: a comprehensive analysis. Eur J Clin Nutr. 2025;79(11):1160-1163. PubMed PMID: 40908328
4. Zahir A, Collins D, Ip S, Samghabadi P, Douglas VC, LaHue SC. Neurological complications associated with rapid weight loss and nutritional deficiencies following GLP-1 agonist use: a case report. BMC Neurol. 2025;26(1):5. PubMed PMID: 41299410
5. Sheth K, Garza E, Saju A, Nazir N, Agarwal A. Wernicke Encephalopathy Associated With Semaglutide Use. Cureus. 2024;16(6):e61783. PubMed PMID: 38975533
6. Crelier VT, Vidal AS, Rezende NB, Figueiredo MR, de Almeida SA, Jorge JK, de Freitas GR. Longitudinal 18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) Findings in Korsakoff Syndrome After Rapid Weight Loss During Tirzepatide Therapy: A Case Report. Cureus. 2026;18(6):e110101. PubMed PMID: 42395251
7. Aasheim ET. Wernicke encephalopathy after bariatric surgery: a systematic review. Ann Surg. 2008;248(5):714-20. PubMed PMID: 18948797
8. Oudman E, Wijnia JW, van Dam M, Biter LU, Postma A. Preventing Wernicke Encephalopathy After Bariatric Surgery. Obes Surg. 2018;28(7):2060-2068. PubMed PMID: 29693218
9. Yu AT, Gross A, Park K, Harvey EJ. Wernicke Encephalopathy After Bariatric Surgery: a Literature Review. Obes Surg. 2023;33(11):3621-3627. PubMed PMID: 37798508
10. Abu-Qasem H, Thalib HI, Ghazi ZS, Tageldin R, Alras Y, Faisal H, Khan L, Ouban A, Yassin-Kassab M. Wernicke encephalopathy in non-alcoholic patients following gastrointestinal procedures: a systematic review. Front Surg. 2026;13:1802386. PubMed PMID: 42453365
11. Thirumalai S, Balamurugan G, Jagdale S, Hussain K, Sayyadi L, Vasu SKA, Turner C, Abuawwad M. The Neurological Impact of Metabolic and Bariatric Surgery: A Systematic Review of Post-Operative Neuropathic and Non-Neuropathic Complications. Clin Obes. 2026;16(5):e70102. PubMed PMID: 42557049
12. Ibrahim T, El Ansari W, Abusabeib A, Yousaf Z, Elhag W. Infrequent but serious? Beriberi And Thiamine deficiency among adolescents and young adults after bariatric surgery. Surg Obes Relat Dis. 2024;20(2):115-126. PubMed PMID: 37620168
13. Gutiérrez-Rey M, Castellar-Visbal L, Acevedo-Vergara K, Vargas-Manotas J, Rivera-Porras D, Londoño-Juliao G, Castillo-Guerrero B, Perdomo-Jiménez MC, Bermúdez V. The Weight of Bariatric Surgery: Wernicke-Korsakoff Syndrome after Vertical Sleeve Gastrectomy-A Case Series. J Pers Med. 2024;14(6):638. PubMed PMID: 38929859
14. Cohen Vig L, Straussberg R, Ziv N, Hirschfeld-Dicker L, Konen O, Aharoni S. Neurologic complications of thiamine (B1) deficiency following bariatric surgery in adolescents. Eur J Paediatr Neurol. 2024;50:74-80. PubMed PMID: 38705013
15. Remelhe Sá S, Lagarteira J, Pera R, Figueiredo A, Batouxas C. Thiamine Deficiency After Bariatric Surgery: Early Neurological Complications and Nutritional Monitoring. Cureus. 2026;18(1):e100637. PubMed PMID: 41635330
16. Kuqo A, Kurti F, Llanaj E. Lower-Limb-Predominant Axonal Sensorimotor Polyneuropathy With Severe Proximal Weakness and Possible Myopathic Involvement After Sleeve Gastrectomy: A Case Report of Delayed Recognition. Clin Case Rep. 2026;14(11):e73813. PubMed PMID: 42964692
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31. Eissa H, Elhassan K, Alzaabi A, Abouelnaga ME, Elbashari M. Shedding Light on the Shadows: A Trio of Neuro-Ophthalmic Cases Emerging From Rapid Weight Loss-Induced Thiamine Deficiency. Cureus. 2025;17(4):e81648. PubMed PMID: 40322396

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1. PubMed: Wernicke encephalopathy with semaglutide or tirzepatide
2. PubMed: Wernicke encephalopathy after bariatric surgery
3. PubMed: thiamine deficiency prevalence and bariatric surgery
4. PubMed: thiamine deficiency and obesity

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Connections

• Thiamine Deficiency (Beriberi) — the hub this page belongs to
• Thiamine for Wernicke-Korsakoff Syndrome — criteria, regimens and the glucose question
• Thiamine Deficiency: Wernicke-Korsakoff Syndrome — the plain-language symptom page
• Wernicke's Encephalopathy — the neurology page
• Dry Beriberi (Nerves) — the nerve damage that often comes with it
• Wet Beriberi (Heart) — the heart form of the same deficiency
• Glucagon-Like Peptide-1 Receptor Agonists — the drug class
• Refeeding Syndrome — the danger when feeding restarts
• Hyperemesis Gravidarum — another setting of prolonged vomiting

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