Extracellular B12 is a measure of B12 present in the serum, reflecting the past 1-7 days nutritional status. In contrast, intracellular B12 is relative to the amount of B12 present inside the white blood cells (WBC), reflecting the past 3-4 week nutritional status.
Can you speak to the difference between intra and extracellular B12 please?
Adair
