Vitamin B1

VITAMIN B1 STATUS, red blood cell (Thiamine)
fE-TKA(B1) ATK 7010

Thiamine is a water-soluble vitamin B1, which is found in the body mainly as thiamine pyrophosphate (TPP). TPP is a coenzyme and plays a role in e.g. carbohydrate metabolism. Reference:

Thiamine is found in the body in the free form and as mono-, di- and triphosphate. Thiamine diphosphate is the physiologically active form of vitamin B1, and it constitutes about 80% of total thiamine. Thiamine deficiency is caused by inadequate and incomplete nutrition or absorption disorder, which can be due to e.g. alcohol, vomiting or intestinal diseases. Some medicines have been found to induce thiamine deficiency (especially diuretics).


​Demonstrating thiamine deficiency. Suspected Wernicke’s disease according to neurological or psychological symptoms. The at-risk groups include alcoholics, malnourished elderly people, frequent vomiters, cancer patients, patients with intestinal disease and patients on parenteral nutrition.


Blood sample. Requires 12 hours of fasting. Glass of water and usual medication are allowed.
No vitamin B1 supplements during 12 hours.


6 – 7 mL ACD or EDTA whole blood (12 h fasting).

Storage and delivery

Whole blood sample: Delivery at room temperature on sampling day. The sample must arrive within 24 hours (Mon-Fri).

If the sample cannot be shipped on sampling day, it must be centrifuged, plasma removed and red blood cells washed with physiological saline. (Add a saline volume equivalent to the plasma volume into the tube, mix the sample and centrifuge. After centrifugation, remove the wash solution.) Finally, the red blood cell mass must be diluted 1:1 with aqua. The dilution is divided into two tubes and it is tested for haemoglobin (B-vit Hb), which is written on the test requisition. The processed sample can be stored refrigerated over the weekend. Delivery at room temperature if it arrives within 24 hours.


Enzymatic method that analyses vitamin B1 (thiamine)-dependent transketolase enzyme activity.

Reference ranges

fE-TKA(B1) 1.01 – 1.31

Turnaround time

10 weekdays


The notified value expresses the ratio of stimulated sample and zero sample. The further the ratio is from 1, the more the body is in need of vitamin B1.