B VitaminOften Deficient

Thiamine (B1)

The energy vitamin. Without thiamine, your cells can't efficiently convert carbohydrates to energy. It's the gatekeeper for the Krebs cycle, essential for nerve function, and one of the first nutrients depleted by alcohol, high sugar intake, and diuretics.

TPP

Active Form

Energy

Gatekeeper

Nerves

Critical For

18 Days

Body Stores

Key Functions

Pyruvate Dehydrogenase

TPP is cofactor for PDH, the enzyme that converts pyruvate to acetyl-CoA - the gateway to the Krebs cycle.

Alpha-Ketoglutarate DH

Another TPP-dependent enzyme in the Krebs cycle. Deficiency bottlenecks energy production at multiple points.

Transketolase

Pentose phosphate pathway enzyme. Makes ribose for DNA/RNA and NADPH for antioxidants.

Nerve Function

Essential for acetylcholine synthesis and nerve conduction. Deficiency causes peripheral neuropathy.

Brain Energy

Brain uses 20% of body's energy. Thiamine deficiency hits the brain hard (Wernicke-Korsakoff).

Carb Processing

Higher carb intake = higher thiamine requirement. Important for diabetics and high-sugar diets.

Who's at Risk for Deficiency

Thiamine stores only last about 18 days. These groups are at higher risk:

Alcohol Use

Alcohol impairs thiamine absorption, increases excretion, and depletes liver stores. Classic cause of Wernicke's.

Diabetes

Increased urinary thiamine loss. High blood sugar increases thiamine demand. Many diabetics are deficient.

Diuretics

Loop diuretics (furosemide) and thiazides increase thiamine excretion. Common in heart failure patients.

Bariatric Surgery

Reduced absorption, rapid weight loss, and vomiting all contribute to deficiency risk.

High-Carb Diets

More carbs = more thiamine needed. Refined carbs provide carbs without the thiamine to process them.

Elderly

Reduced absorption, medications, and lower food intake all increase deficiency risk.

Deficiency Syndromes

Beriberi

Wet beriberi: Heart failure, edema, shortness of breath
Dry beriberi: Peripheral neuropathy, muscle weakness, pain
Common in polished rice diets (historically)
Still seen in alcoholism and severe malnutrition

Wernicke-Korsakoff

Wernicke: Confusion, ataxia, eye movement problems
Korsakoff: Memory loss, confabulation (permanent)
Medical emergency - requires IV thiamine
Don't give glucose before thiamine (worsens it)

Forms and Supplementation

Forms

• Thiamine HCl: Standard form, water-soluble, limited absorption
• Benfotiamine: Fat-soluble, 5x better absorption, best for neuropathy
• TTFD (Allithiamine): Crosses blood-brain barrier, good for brain
• Sulbutiamine: Synthetic, crosses BBB, used for fatigue

Typical Doses

• RDA: 1.1-1.2mg (often inadequate)
• General support: 50-100mg thiamine HCl
• Diabetic neuropathy: 300-600mg benfotiamine
• Requires: Magnesium for activation to TPP

Food Sources

Thiamine is water-soluble and destroyed by heat, alkaline conditions, and sulfites:

Best Sources

Pork, sunflower seeds, black beans, lentils, nutritional yeast, whole grains.

Good Sources

Fish, nuts, fortified cereals, green peas, asparagus, acorn squash.

Watch Out

Cooking destroys thiamine. Raw fish contains thiaminase (destroys B1). Tea/coffee can inhibit absorption.