Causes and early diagnosis of vitamin B12 deficiency
Herrmann, Obeid · 2008 · Deutsches Arzteblatt International 105(40):680-685
What this work gives Aellic
Holotranscobalamin (active B12) is the earliest marker of a negative B12 balance; the review treats values below 35 pmol/l as lowered, and lowered holotranscobalamin with raised methylmalonic acid as a metabolically manifest deficiency.
Correction of 25 October 2026
The registry said a deficiency becomes likely below 35 pmol/l. The review calls such values lowered and treats a lowered value alone as depletion; a metabolically manifest deficiency needs raised methylmalonic acid as well.
The entry on the register was wrong. It was not replaced but kept, with what holds instead standing next to it.
Where this sits in the engine
This work is on the register, but nothing computes with it today, mostly because the feature it belongs to has not been built yet. It is listed so the numbers on the overview do not claim more than they carry.