[Apport of serum vitamin B12 determination in the diagnosis of deficiency: about 95 cases]. / Apport du dosage de la vitamine B12 serique dans le diagnostic d'une carence: a propos de 95 cas.

Vitamin B12 belong a group of cobalamins. It's known to be an enzymatic cofactor of many metabolic reactions essentially in the synthesis of DNA. Damage of deficiency are various essentially hematologic and neurologic. Macrocytic anaemia constitute the main disorder of vitamin B12 deficiency. However, Vitamin B12 deficiency is common in the elderly with neuropsychiatric disorders whether macrocytic anaemia is present or not as its development may come later. In a study we investigate 95 patients aged 21 to 85 years (29 men, 20 women) with symptoms of vitamin B12 deficiency. First, vitamin B12 serum were measured by immuno enzymatic method (MEIA Abbott). Values were classified among 4 categories characterised on manufacture norms; low: 41 cases, unspecified: 19 cases, normal: 13 cases and high: 22 cases. Secondly, the concordance between Vitamin B12 serum, clinical history and evolution were evaluated. The Kappa index established showed a satisfactory result (= 0.97).