Vitamin B1 – Thiamin
Description - Thiamin is water soluble and part of the B-group vitamins
Function - Thiamin aids the nervous system and is essential for the
functioning of some important enzymes. These enzymes have
vital roles in the processes that make energy available in the
body. Thiamin is essential for the transmission of certain types of
nerve signal between the brain and the spinal cord.
Human Requirements – Thiamine requirements depend on energy intake; values are
therefore often given as mg/1000 kcal and also as total values
based on estimated average energy requirements for the
majority of people in the UK EU RDA: 1.4mg
Dietary Intake – In the UK, the average adult diet provides: for men, 2.0mg daily;
for women, 1.54mg
Food Sources – Brown rice, peas, beans and other vegetables, fortified breakfast
cereals, and wholemeal breads and cereals, pork, bacon and
Deficiency Symptoms – Thiamine deficiency may lead to beri-beri (rare in the UK).
Deficiency is associated with abnormalities of carbohydrate
metabolism. Early signs of deficiency include depression, poor
memory, muscle weakness and stiffness, nerve tingling, burning
sensation and numbness, tiredness, headache, loss of appetite
Precautions / Contra-Indications – Known hypersensitivity to thiamine.
Safe Upper Level: 100mg
Pregnancy & Breastfeeding – Thiamine is suitable to be taken during pregnancy and
Adverse Effects – There appear to be no toxic effects (except possibly gastric
upset) with high oral doses. There have however been rare
reports of anaphylactic reactions (coughing, difficulty in
breathing and swallowing, flushing, skin rash, swelling of face,
lips and eyelids).
Interactions – Excessive alcohol intake induces thiamine deficiency. Adequate
amounts of all B vitamins are required for optimal functioning;
deficiency or excess of one B vitamin may lead to abnormalities
in the metabolism of another.