Vitamin B1 (or Thiamine or thiamin or aneurine) is one of the 8 water-soluble vitamins available from food sources as well as from supplements . It was one of the first B vitamins identified .
Total thiamine content in an adult human is estimated to be around 30 mg and is located in the skeletal muscles, heart, brain, liver and kidneys. It has a biological half-life of around 9 – 18 days [2,4].
Alcohol and other anti-thiamin factors that present in some foods (such as some phenolic compounds, sulfites and thiaminases)) can reduce thiamin’s bioavailability .
- In healthy individuals, the thiamine absorption rate is around 95% for intake lower than 2 mg/day. 
- It is absorbed in the small intestine. 
- It is believed that thiamin absorption increases when intakes are low and decreases above an intake of 5mg/day. [1,4]
- Also, heating, cooking, processing foods or boiling them in water can destroy the thiamine content in foods. 
- This water-soluble vitamin is usually stored in the liver is very low amounts and has a very short half-life. 
- It can be stored in the liver for a maximum of 18 days, hence daily intake is recommended. 
- The body excretes excess thiamine in the urine when intakes are high and significant excretions happens in faeces when daily consumption is above 5 mg/day. [1,4]
Recommended Daily Intake
Thiamine Food Sources
Excessive Intake/ Toxicity Side Effects
Toxicity is rare for this nutrient as it’s a water-soluble vitamin and the body removes excess amount instantly [1,2,4].
Groups At Risk of Thiamine Deficiency
Thiamine Interaction With Other Nutrients
- Magnesium – Magnesium deficiency can possibly aggravate thiamin deficiency in humans .
- Carbohydrate – Excess intake of carbs may possibly increase Thiamine intake.