Article Text

Download PDFPDF
Low vitamin B-12 status in confirmed Alzheimer’s disease as revealed by serum holotranscobalamin
  1. H Refsum1,
  2. A D Smith2
  1. 1Department of Pharmacology, University of Oxford, Oxford, UK
  2. 2Oxford Project to Investigate Memory and Aging (OPTIMA), Department of Pharmacology, University of Oxford
  1. Correspondence to:
 Professor A David Smith, University Department of Pharmacology, Mansfield Rd, Oxford OX1 3QT, UK;


Objective: To examine the possible association of holotranscobalamin, the active fraction of serum cobalamin, with Alzheimer’s disease.

Methods: 51 patients with pathologically confirmed Alzheimer’s disease and 65 cognitively screened elderly controls were studied. Serum holotranscobalamin was measured by a new solid phase radioimmunoassay.

Results: Geometric mean levels showed no significant case–control differences for serum total cobalamin, but lower levels of holotranscobalamin in Alzheimer’s disease (41.1 pmol/l) than in controls (57.1 pmol/l) (p < 0.001). The odds ratio of Alzheimer’s disease was significant for low holotranscobalamin but not for low total cobalamin.

Conclusions: Disturbed cobalamin status is common in Alzheimer’s disease and accordingly measurement of holotranscobalamin should be considered in the assessment of cognitively impaired patients.

  • vitamin B-12
  • Alzheimer’s disease
  • holotranscobalamin

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Competing interests: Both authors have had costs to participate in scientific meetings reimbursed by Axis-Shield Ltd.