Vitamin B6

VITAMIN B6 STATUS, red blood cell (Pyridoxal phosphate)
​fE-ASATA(B6) ATK 8021

Pyridoxine vitamers, commonly known as vitamin B6, encompass a group of substances with vitamin B6 activity. This group includes free pyridoxine, pyridoxal, and pyridoxamine. Being water-soluble, pyridoxine functions as a coenzyme within the body, particularly in crucial processes like amino acid and carbohydrate metabolism.



Indicating pyridoxal phosphate deficiency.


Blood sample. Requires 12 hours of fasting. Glass of water and usual medication are allowed.

No vitamin B6 supplements during 12 hours. 


6 – 7 mL Li-hep 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). DO NOT FREEZE!

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 hemoglobin (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 B6 (pyridoxine)-dependent aspartate aminotransferase enzyme activity. 

Turnaround time

10 weekdays

Reference ranges, calculated

fE-ASATA(B6) 0.41 – 0.81

Interpretation of results

The provided figure represents the relationship between the blank sample and the stimulated sample. A larger deviation from 1 signifies a greater requirement for vitamin B6 within the body.


Last update 8.8.2023