Vitamin B1 (Thiamine) whole blood test

What is Vitamin B1 (Thiamine) whole blood test?

Vitamin B1 is a water-soluble vitamin that performs multiple vital functions in the body. It has a critical role in energy metabolism, cell growth, development and functioning. 

Since excess of this vitamin gets excreted out through the kidneys, it is important to take thiamine regularly in diet otherwise, a deficiency can occur in 10 days. Severe thiamine deficiency can develop in 21 days if you are on a restricted intake.

The daily recommended dietary allowance of thiamine for adults is 1.2 mg in males and 1.1 mg in females. The recommended total dietary intake increases from childhood into adulthood and during pregnancy and breastfeeding. 

We get thiamine from dietary sources such as whole grains, meat, fish, and fortified foods such as cereals, bread and infant formula. We can also get thiamine from vitamin supplements.

However, instead of determining vitamin B1 level, this test measures the levels of  Thiamine diphosphate (TDP) - the main metabolically active form of thiamine, which constitutes nearly 80% of the vitamin B1 in the body. 

Thiamine and thiamine monophosphate, the other forms of vitamin B1, are not measured. A whole blood sample (instead of plasma test) is preferred as approximately 80% of the thiamine is present in the red blood cells.

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