What is the role of Thiamine (Vitamin B1) supplementation?

From the Guidelines

Thiamine supplementation is crucial for individuals with deficiency, alcoholism, or certain medical conditions, and the standard oral dose is 100mg daily for mild deficiency, while severe cases may require 200-300mg daily in divided doses, as recommended by the most recent guideline 1.

Key Considerations

• The dose of thiamine supplementation varies depending on the clinical situation, with mild deficiency requiring 10 mg/day for a week, followed by 3-5 mg/daily for at least 6 weeks, while chronic diuretic therapy suggests 50 mg a day, by mouth 1.
• In cases of high suspicion or proven deficiency, 200 mg, 3 times a day, IV is recommended, and for encephalopathy of uncertain etiology, including Wernicke encephalopathy, 500 mg, 3 times a day, IV is suggested 1.
• The maintenance dose in proven deficiency is 50-100 mg/day, orally, and in refeeding syndrome, 300 mg IV before initiating nutrition therapy, 200-300 mg IV daily for at least 3 more days is recommended 1.

Clinical Context

• Thiamine supplementation is essential before administering glucose to malnourished patients or alcoholics, as glucose metabolism increases thiamine requirements and can precipitate deficiency symptoms 1.
• In patients with severe ASH, parenteral nutrition (PN) should be delivered like in other critically ill patients, and water-soluble and fat-soluble vitamins, as well as electrolytes and trace elements, should be administered daily from the beginning of PN 1.

Important Notes

• The oral route is adequate in cases of suspicion of chronic deficiency without any acute disease, while the IV route is recommended in cases of acute disease or suspicion of inadequate intake, even short-term 1.
• Side effects are rare with oral supplementation, though IV administration may occasionally cause allergic reactions, and for prevention, a multivitamin containing 1.1-1.2mg of thiamine daily is typically sufficient for most healthy adults.

From the FDA Drug Label

Clinical Pharmacology The water soluble vitamins are widely distributed in both plants and animals. They are absorbed in man by both diffusion and active transport mechanisms These vitamins are structurally diverse (derivatives of sugar, pyridine, purines, pyrimidine, organic acid complexes and nucleotide complex) and act as coenzymes, as oxidation-reduction agents, possibly as mitochondrial agents. Thiamine combines with adenosine triphosphate (ATP) to form thiamine pyrophosphate, also known as cocarboxylase, a coenzyme Its role in carbohydrate metabolism is the decarboxylation of pyruvic acid in the blood and -ketoacids to acetaldehyde and carbon dioxide.

The role of Thiamine (Vitamin B1) supplementation is to act as a coenzyme in carbohydrate metabolism, specifically in the decarboxylation of pyruvic acid and -ketoacids. Thiamine supplementation is necessary to prevent vitamin B1 deficiency, which can occur after approximately three weeks of total absence of thiamine in the diet, and is especially important when the carbohydrate content of the diet is raised 2.

• Key points:
  • Thiamine is a coenzyme in carbohydrate metabolism
  • Thiamine deficiency can occur after three weeks without thiamine in the diet
  • Thiamine requirement is greater with high carbohydrate diets

From the Research

Role of Thiamine Supplementation

Thiamine, also known as Vitamin B1, plays a crucial role in various biological processes, particularly in glucose metabolism 3. The biologically active form of thiamine, thiamin pyrophosphate (TPP), is a cofactor in macronutrient metabolism and is essential for nerve structure and function, as well as brain metabolism 4.

Benefits of Thiamine Supplementation

The benefits of thiamine supplementation include:

• Correcting lactic acidosis, improving cardiac function, and treating delirium in critically ill patients 5
• Preventing and treating thiamine deficiency (TD) in patients at risk, such as those with malnutrition, alcoholism, or undergoing surgical procedures 4, 5, 6
• Treating Wernicke's encephalopathy and Korsakoff's syndrome, which are complications of thiamine deficiency 4, 6, 7

Patient Groups that Benefit from Thiamine Supplementation

Patient groups that may benefit from thiamine supplementation include:

• Critically ill patients, particularly those with sepsis, heart failure, or undergoing surgical procedures 5, 3
• Patients with alcohol dependence, as thiamine deficiency is common in this population 6
• Patients with malnutrition, refeeding syndrome, or gastrointestinal surgery 4, 3
• Patients at risk of thiamine deficiency, such as those with increased urinary excretion or acute metabolic stress 5

Dosage and Administration

The optimal dosage and administration of thiamine supplementation vary depending on the patient group and clinical scenario. Studies suggest that:

• Parenteral thiamine 200-500mg three times a day may be effective in treating Wernicke's encephalopathy 6
• High-dose thiamine (>100mg IV daily) may be prescribed for patients with suspected Wernicke's encephalopathy or those at high risk of thiamine deficiency 7
• Oral thiamine 250-1000mg/day may be effective in preventing and treating thiamine deficiency in patients at risk 6, 3