Vitamins

Vitamin B1 (Thiamin)

An essential water-soluble vitamin crucial for energy metabolism, nerve function, and cardiovascular health

Quick Facts

Daily Needs

1.1-1.2 mg for adults, with variations based on age, sex, and life stage

Importance

Thiamin is essential for carbohydrate metabolism, nerve signal transmission, muscle contraction, and heart function.

Key Functions

  • Carbohydrate metabolism for energy production
  • Nerve signal transmission
  • Muscle contraction
  • Heart function maintenance
  • Brain glucose utilization
  • Fat and protein metabolism
  • RNA and DNA synthesis
  • Antioxidant activity
  • Supports immune function
  • Production of hydrochloric acid for digestion

Deficiency Signs

  • Fatigue and weakness
  • Loss of appetite
  • Irritability
  • Reduced reflexes
  • Muscle wasting
  • Poor coordination
  • Numbness or tingling in extremities
  • Mental confusion
  • Short-term memory loss
  • Cardiovascular problems (enlarged heart, rapid heart rate)
  • In severe cases (beriberi): edema, heart failure, or Wernicke-Korsakoff syndrome

Excess Signs

  • Generally considered non-toxic in high doses
  • Headache
  • Nausea
  • Irritability
  • Insomnia
  • Rapid pulse
  • Weakness
  • Contact dermatitis (rare)

Best Food Sources

  • Whole grains (brown rice, whole wheat)
  • Fortified cereals and bread products
  • Pork
  • Fish (trout, tuna)
  • Legumes (black beans, lentils)
  • Seeds (sunflower, flax)
  • Nuts (macadamia, pistachio)
  • Nutritional yeast
  • Green peas
  • Asparagus
  • Oranges

Absorption Facts

  • Water-soluble - excess is excreted in urine
  • Absorbed in the small intestine
  • Alcohol significantly impairs absorption
  • Absorption decreases with age
  • Raw fish, tea, coffee, and betel nuts contain thiaminases that destroy thiamin
  • Cooking can destroy significant amounts (25-45%)
  • Absorption reduced by folate deficiency
  • Some medications reduce absorption (diuretics, phenytoin)
  • Storage in the body is limited (up to 30 mg)

Special Considerations

  • Alcoholics have increased requirements and are at high risk for deficiency
  • Diuretic medications increase thiamin excretion
  • Pregnancy and breastfeeding increase needs
  • Those with malabsorption conditions may need more
  • Refined grain products lose most thiamin during processing
  • Heavy physical activity increases requirements
  • High carbohydrate intake increases thiamin needs
  • Deficiency is common in developing countries where polished rice is a staple
  • Obesity may impair thiamin metabolism

About Vitamin B1 (Thiamin)

Loading nutrient information...

Track your Vitamin B1 (Thiamin) intake with Microgram