What supplement is deficient in wet beriberi?

Thiamine (Vitamin B1) Deficiency in Wet Beriberi

Thiamine (vitamin B1) is the deficient supplement in wet beriberi, characterized by cardiovascular manifestations including cardiac insufficiency with tachycardia and respiratory symptoms. 1

Clinical Presentation of Wet Beriberi

Thiamine deficiency manifests in different clinical forms:

• Wet Beriberi: Primarily cardiovascular manifestations

  • Heart failure with high cardiac output
  • Tachycardia
  • Respiratory symptoms
  • Edema
  • In severe cases (Shoshin beriberi): Biventricular failure with metabolic acidosis 2

• Dry Beriberi: Primarily neurological manifestations

  • Peripheral neuropathy
  • Muscle weakness
  • Neuritis especially in lower limbs 1, 3

• Wernicke's Encephalopathy: Cerebral manifestations

  • Ataxia
  • Confusion
  • Coma 1

Pathophysiology

Thiamine is an essential water-soluble vitamin that:

• Functions as a cofactor for enzymes involved in carbohydrate metabolism
• Is not synthesized in humans, requiring continual dietary intake
• Has minimal body storage, making deficiency possible within weeks of inadequate intake 4

In wet beriberi, thiamine deficiency leads to:

• Impaired cellular energy production
• Cardiovascular dysfunction
• Lactic acidosis due to impaired aerobic metabolism
• High-output cardiac failure 2

Risk Factors for Thiamine Deficiency

• Prolonged vomiting
• Rapid weight loss
• Poor dietary intake
• Alcohol abuse
• Edema
• Post-bariatric surgery
• Chronic gastrointestinal illness
• Malabsorption syndromes 1, 5, 6

Diagnosis

Thiamine deficiency should be suspected in patients with:

• Unexplained heart failure, especially with high cardiac output
• Lactic acidosis without clear etiology
• Risk factors for malnutrition
• Peripheral neuropathy with cardiovascular symptoms 2, 6

Laboratory assessment:

• Measuring RBC or whole blood thiamine diphosphate (ThDP) is the preferred method 5
• Serum thiamine levels may be undetectable in severe deficiency 7

Treatment

Immediate thiamine replacement is essential and should not be delayed pending test results in suspected cases. 1

Dosing recommendations:

• For severe deficiency (wet beriberi):

  • Initial: 100 mg intravenous thiamine as loading dose 2
  • Maintenance: 50-100 mg/day oral thiamine 5

• For high-risk patients:

  • Prophylactic: 15 mg oral thiamine daily
  • If symptomatic: Increase to 200-300 mg daily 5

Clinical Response

Proper thiamine replacement typically results in:

• Rapid increase in urine output
• Correction of metabolic acidosis
• Reduction in pulmonary-capillary wedge pressure
• Normalization of cardiac output 2
• Improvement in mental status if encephalopathy is present 6

Prevention

For high-risk individuals:

• Regular thiamine supplementation (15-25 mg/day)
• Multivitamin supplementation containing thiamine
• Prophylactic thiamine administration before giving IV dextrose to individuals with marginal thiamine status 8

Important Clinical Considerations

• Thiamine should be administered before glucose in malnourished patients to prevent precipitating or worsening heart failure 8
• Patients on diuretics have increased urinary excretion of thiamine and are at higher risk for deficiency 4
• Thiamine deficiency can mimic other conditions like Guillain-Barré syndrome, leading to misdiagnosis and inappropriate treatment 3

Early recognition and prompt treatment of thiamine deficiency in wet beriberi can prevent rapid progression to low cardiac output failure and sudden death 2.