Category: biosynthesis
Thiamine = vitamin B1. Active form: thiamine pyrophosphate (TPP), cofactor for pyruvate dehydrogenase (PDH), α-ketoglutarate dehydrogenase (TCA), transketolase (PPP), and branched-chain α-ketoacid dehydrogenase (BCAA catabolism). Deficiency causes: BERIBERI (wet = high-output CHF; dry = peripheral neuropathy) when chronic; WERNICKE encephalopathy (acute confusion + ataxia + ophthalmoplegia) when acute — classic in alcoholism + hyperemesis gravidarum + bariatric surgery + chronic vomiting. Korsakoff syndrome = chronic memory deficit residual to untreated Wernicke. Glucose load WITHOUT thiamine repletion can precipitate Wernicke (the "give thiamine before glucose" ED rule). High-dose IV thiamine (500 mg q8h × 3 days) is first-line treatment.