Vitamin B1 (thiamine)
Thiamine is a water soluble vitamin of the B complex group. One of it's phosphate derivates, thiamine pyrophosphate (TPP), is a coenzyme in the following enzymatic reactions:
Thiamine is therefore important in the catabolism of sugars and aminoacids. The clinical consequences of thiamine deficiency are therefore seen first in highly aerobic tissues such as the brain (Wenicke-Korsakoff syndrome) and the heart (wet beriberi).
Causes of thiamine deficiency:
Conditions associated with thiamine deficiency:
- pyruvate dehydrogenase complex
- pyruvate decarboxylase in ethanol fermentation
- alpha-ketoglutarate dehydrogenase complex
- branched-chain amino acid dehydrogenase complex
- 2-hydroxyphytanoyl-CoA lyase
- transketolase
Thiamine is therefore important in the catabolism of sugars and aminoacids. The clinical consequences of thiamine deficiency are therefore seen first in highly aerobic tissues such as the brain (Wenicke-Korsakoff syndrome) and the heart (wet beriberi).
Causes of thiamine deficiency:
- alcohol excess
- malnutrition
Conditions associated with thiamine deficiency:
- Wernicke's encephalopathy: nystagmus, ophthalmoplegia and ataxia
- Korsakoff's syndrome: amnesia, confabulation
- dry beriberi: peripheral neuropathy
- wet beriberi: dilated cardiomyopathy