What are the presentations and treatment options for Vitamin B1 (Thiamine) deficiency?

Presentations and Treatment of Vitamin B1 (Thiamine) Deficiency

Thiamine deficiency presents in several distinct clinical syndromes including Wernicke-Korsakoff syndrome, dry beriberi (neurological), wet beriberi (cardiovascular), and gastrointestinal beriberi, requiring prompt parenteral thiamine administration at doses of 500 mg IV three times daily for 3-5 days in cases of Wernicke's encephalopathy to prevent irreversible neurological damage and mortality. 1

Clinical Presentations of Thiamine Deficiency

Wernicke-Korsakoff Syndrome

• Classic triad: Ophthalmoplegia, ataxia, and mental confusion/encephalopathy 2, 3
• Often underdiagnosed, especially when the full triad is not present
• May progress to Korsakoff syndrome (irreversible memory impairment) if not treated promptly
• MRI findings: High signal intensity on T2-weighted images in brainstem, thalamus, and mammillary bodies 4

Dry Beriberi (Neurological)

• Peripheral neuropathy with sensory-motor symptoms
• Paresthesia of limbs (often starting in lower extremities)
• Muscle weakness and pain
• Can mimic Guillain-Barré syndrome 2
• Bilateral lower extremity weakness 5

Wet Beriberi (Cardiovascular)

• High-output heart failure
• Peripheral edema
• Tachycardia
• Hypotension requiring vasopressors in severe cases 2
• Must be treated as an emergency cardiac condition 6, 7, 8

Gastrointestinal Beriberi

• Intractable nausea and vomiting
• Abdominal pain
• Can lead to multisystem involvement 5

Metabolic Manifestations

• Anion gap metabolic acidosis 5
• Lactic acidosis

High-Risk Populations for Thiamine Deficiency

• Alcohol use disorder patients 1, 9
• Post-bariatric surgery patients 1
• Patients with prolonged vomiting or malabsorption 1, 5
• Patients at risk for refeeding syndrome 1
• ICU patients with malnutrition 1
• Patients on prolonged parenteral nutrition without adequate supplementation 1, 4
• Patients with liver cirrhosis, particularly alcoholic liver disease 1
• Patients receiving dextrose-containing fluids without thiamine supplementation 1, 6, 7, 8

Treatment Recommendations

Wernicke's Encephalopathy

• Initial treatment: 500 mg thiamine IV three times daily for 3-5 days 1
• Followed by 250 mg IV daily for at least 3-5 additional days 1
• Alternative regimen: 100 mg IV initially, followed by 50-100 mg IM daily until regular diet is resumed 6, 7, 8
• For suspected cases: 250-300 mg IV twice daily for 3-5 days, then oral thiamine 250-300 mg/day 9

Beriberi

• Wet beriberi with cardiac involvement: Emergency treatment with slow IV thiamine administration 6, 7, 8
• Dry beriberi: 10-20 mg thiamine IM three times daily for up to two weeks 6, 7, 8
• Maintenance: Oral therapeutic multivitamin with 5-10 mg thiamine daily for one month 6, 7, 8
• Infantile beriberi: Mild cases may respond to oral therapy; for collapse, cautious IV administration of 25 mg 6, 7, 8

Preventive Therapy in High-Risk Patients

• Patients receiving dextrose: 100 mg thiamine in each of the first few liters of IV fluid 6, 7, 8
• High-risk patients: 100-300 mg/day IV thiamine 1
• Patients on TPN: At least 2.5 mg/day thiamine 1
• Enteral nutrition: 1.5-3 mg/day thiamine (for patients receiving 1500 kcal/day) 1

Important Clinical Considerations

• Administer thiamine before glucose-containing fluids to prevent precipitating acute thiamine deficiency 1
• Rapid clinical improvement (within 48 hours) after thiamine administration supports the diagnosis 2, 3
• Correct poor dietary habits and prescribe a balanced diet 6, 7, 8
• Monitor for refeeding syndrome in malnourished patients 5
• Thiamine deficiency should be considered in all patients with malabsorption, malnutrition, and malignancies 4

Common Pitfalls to Avoid

• Misdiagnosis: Thiamine deficiency can mimic other neurological disorders like Guillain-Barré syndrome 2
• Delayed treatment: Prompt diagnosis and treatment are essential to prevent irreversible neurological damage 4, 3
• Inadequate dosing: Higher doses are needed for Wernicke's encephalopathy than for prophylaxis 1, 9
• Oral supplementation in malabsorption: Patients with malabsorption may not adequately absorb oral thiamine 4
• Failure to recognize atypical presentations: The classic triad of Wernicke's encephalopathy is not always present, especially in children 4
• Blind supplementation: Not all alcoholics have vitamin deficiencies; some may have excess levels 1