Translations:Vitamin B12/28/en
Serum haptocorrin binds 80-90% of circulating B12, rendering it unavailable for cellular delivery by transcobalamin II. This is conjectured to be a circulating storage function. Several serious, even life-threatening diseases cause elevated serum HC, measured as abnormally high serum vitamin B12, while at the same time potentially manifesting as a symptomatic vitamin deficiency because of insufficent vitamin bound to transcobalamin II which transfers the vitamin to cells.