Causes of Thiamine Deficiency
Thiamine deficiency is primarily caused by alcohol use disorder, malnutrition, increased metabolic demands, malabsorption conditions, and prolonged parenteral nutrition without adequate supplementation. 1
High-Risk Populations
Specific populations at increased risk of thiamine deficiency include:
- Alcohol use disorder patients - Most common risk factor 1, 2
- Post-bariatric surgery patients - Due to reduced absorption 1
- Patients with prolonged vomiting or diarrhea - Leading to inadequate intake and increased losses 1
- Critically ill patients - Due to increased metabolic demands 1, 3
- Patients at risk of refeeding syndrome - Increased utilization during refeeding 1
- Liver cirrhosis patients - Particularly those with alcoholic liver disease 1
- Cancer patients - Especially those with appetite loss for more than two weeks 4
- Elderly and institutionalized individuals - Due to poor dietary intake 1
- Individuals on calorie-restricted diets - Insufficient intake 1
Pathophysiological Mechanisms
Thiamine deficiency develops through several mechanisms:
- Insufficient dietary intake - Body stores of thiamine are limited (25-30 mg) and dependent on regular dietary intake 5
- Short half-life - The active forms of thiamine have a relatively short half-life, requiring consistent replenishment 5
- Increased metabolic demands - Oxidative stress and systemic inflammation in critical illness rapidly deplete thiamine stores 5, 3
- Malabsorption - Thiamine absorption can be inhibited by alcohol consumption or folate deficiency 5
- Increased glucose administration - High glucose loads without adequate thiamine can precipitate acute deficiency 1, 6
Biochemical Basis
Thiamine plays crucial roles in:
- Carbohydrate metabolism - As a coenzyme for pyruvate dehydrogenase 5, 6
- Energy production - Essential for ATP formation 5, 6
- Neurotransmitter synthesis - Important for nervous system function 7
- Mitochondrial function - Deficiency leads to mitochondrial dysfunction 8, 7
Clinical Manifestations
Thiamine deficiency can present as:
- Wernicke-Korsakoff syndrome - Neurological disorder with encephalopathy 2, 7
- Dry beriberi - Neurological signs and symptoms 3
- Wet beriberi - Cardiovascular manifestations 3
- Subclinical deficiency - May present with non-specific symptoms like appetite loss 4
Important Clinical Considerations
- Thiamine deficiency can develop after approximately three weeks of total absence from the diet 6
- Administering glucose before thiamine can precipitate or worsen thiamine deficiency 1
- Thiamine should be administered before any glucose-containing fluids in at-risk patients 1
- Subclinical thiamine deficiency may occur in cancer patients even without typical signs of Wernicke encephalopathy 4
Prevention
- Thiamine supplementation for high-risk individuals 1
- Food fortification (e.g., flour) is an effective public health measure 2
- Early recognition and treatment of conditions that increase risk 3
- Adequate nutritional support with appropriate thiamine content for patients on enteral or parenteral nutrition 5, 1
Thiamine deficiency remains a significant clinical concern despite being easily preventable and treatable. Early recognition of risk factors and prompt supplementation can prevent serious neurological and cardiovascular complications.