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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)
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