Vitamin B2

VITAMIN B2 STATUS, red blood cell (Riboflavin)
fE-GRA(B2) ATK 7011

Riboflavin (vitamin B2) is a water-soluble vitamin that is essential for humans. It is needed for many metabolic functions. It is essential for e.g. healthy skin, nail and hair. Flavin nucleotides – coenzymes that are vital for redox reactions – contain riboflavin.


Demonstrating vitamin B2 deficiency.


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

No vitamin B2 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 B2 (riboflavin)-dependent glutathione reductase enzyme activity. 

Reference ranges

fE-GRA(B2) 1.02 – 1.68

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 B2.