[Anemia caused by vitamin B 12 deficiency in subjects aged over 75 years: new hypotheses. A study of 20 cases]

Rev Med Interne. 2000 Nov;21(11):946-54. doi: 10.1016/s0248-8663(00)00250-2.
[Article in French]


Purpose: New hypotheses have recently been developed on vitamin B12 deficiency and the frequently observed occurrence in the elderly subject of food cobalamin malabsorption, i.e., the non-dissociation of B12 and its carrier protein (ND B12), and the possibility of rectifying this imbalance by oral crystalline B12 supplementation. The aim of this study was therefore to confirm these hypotheses in a series of patients aged over 75 years with anemia due to B12 deficiency.

Methods: A retrospective study was carried out over a 5-year period on patients aged over 75 years presenting with megaloblastic anemia (hemoglobin [Hb] < 12 g/dL) and vitamin B12/cobalamin deficiency (B12 < 160 pg/mL).

Results: Twenty cases were analyzed. The average age of the patient population was 82.5 +/- 6 years, and the F/M sex ratio was 1:2. Mean Hb levels were 7.9 +/- 2.4 g/dL, mean serum B12 levels were 83 +/- 24 pg/mL, and mean homocysteinemic levels were 35 +/- 27 mumol/L. The diagnosis was as follows: food cobalamin malabsorption/ND B12 (n = 10), Biermer's disease/pernicious anemia (n = 5), malabsorption due to pancreatic insufficiency (n = 1), and low dietary B12 levels (n = 1). Disorders associated with ND B12 were: atrophic gastritis and Helicobacter pylori infection (n = 6), antacid or biguanide intake (n = 3), alcohol abuse (n = 2), or idiopathic syndrome (n = 2). In the patients who were followed up (n = 10), i.m. (n = 5) or oral (n = 5) administration of crystalline B12 resulted in the correction of hematological abnormalities.

Conclusion: In the elderly subject, food cobalamin/ND B12 malabsorption appears to be the main cause of B12 deficiency, and is frequently associated with atrophic gastritis. In these cases, administration of oral crystalline B12 may be an efficient means of treating this disorder.

Publication types

  • English Abstract

MeSH terms

  • Aged
  • Aged, 80 and over / physiology*
  • Anemia, Megaloblastic / drug therapy
  • Anemia, Megaloblastic / etiology*
  • Carrier Proteins / metabolism
  • Female
  • Humans
  • Malabsorption Syndromes / complications*
  • Male
  • Retrospective Studies
  • Vitamin B 12 / blood
  • Vitamin B 12 / metabolism
  • Vitamin B 12 / therapeutic use*
  • Vitamin B 12 Deficiency / complications*


  • Carrier Proteins
  • Vitamin B 12