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Vitamin B1 (thiamine)

Essential nutrient with EFSA claims for nervous system, heart, energy metabolism, and psychological function, clinically critical in alcohol use and bariatric contexts.

Why

Vitamin B1 (thiamine) is essential for glucose metabolism, neuronal function, and cardiac function. EFSA has authorised health claims covering normal carbohydrate energy metabolism, normal heart function, normal psychological function, and normal nervous system function. Deficiency causes beriberi (wet and dry forms) and Wernicke-Korsakoff syndrome, clinically important in alcohol use disorder, severe malnutrition, hyperemesis, and bariatric surgery. Benfotiamine (lipid-soluble) has additional preliminary use in diabetic neuropathy.

How it works

Cofactor (as thiamine pyrophosphate) for pyruvate dehydrogenase, α-ketoglutarate dehydrogenase, and transketolase, central enzymes of glucose metabolism and the pentose-phosphate pathway. Required for nerve myelin maintenance and neurotransmitter synthesis (acetylcholine, GABA).

Expected onset · Symptomatic deficiency improvement within days; chronic neuropathy support over months

How to take

Dosage

RDI: 1.1–1.2 mg/day. Wernicke prophylaxis (clinical context): 200–300 mg/day oral; severe at-risk patients receive parenteral thiamine first. Benfotiamine for neuropathy: 300–600 mg/day.

Timing

With or without food

On the label

'Thiamine HCl' (basic form) or 'benfotiamine' (lipid-soluble, better bioavailability for neuropathy use). Stated milligrams per serving.

Ideal for

Adults with alcohol use disorder; people on dialysis or post-bariatric-surgery; hyperemesis gravidarum; refeeding syndrome risk; suspected high-output cardiac failure with low intake.

Safety

Very wide safety margin, water-soluble, renal excretion handles excess. IV high-dose thiamine: rare anaphylactic reactions reported. In severe alcohol use disorder or refeeding context: administer thiamine BEFORE glucose to prevent precipitated Wernicke encephalopathy. Pregnancy: hyperemesis is an active indication; dietary requirement is increased.

Evidence

At a glance

EFSA-authorised claims cover four separate functions. Sechi 2007 Lancet Neurol provides the clinical-context anchor for Wernicke-Korsakoff prevention and treatment, with very high mortality of untreated cases. Stracke 2008 BENDIP RCT: benfotiamine 300/600 mg/day reduced symptomatic diabetic neuropathy scores over 6 weeks.

Where to get it

Shop Vitamin B1 (thiamine) on Amazon

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