Importance of holotranscobalamin (holoTC) measurements in early diagnosis of cobalamin deficiency, especially in patients with borderline vitamin B12 concentrations Kobalamin eksikliǧinin erken tanisinda, özellikle vitamin B12 düzeyleri sinirda olan hastalarda, holotranskobalamin (holoTC) ölçümünün önemi

Sönmezişik F., Gür E., Asiltaş B.

Nobel Medicus, vol.9, no.2, pp.15-20, 2013 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 9 Issue: 2
  • Publication Date: 2013
  • Journal Name: Nobel Medicus
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.15-20


Objective: Subclinical vitamin B12 deficiency and adverse health outcomes are of general concern. Current biomarkers of vitamin B12 status are not always satisfactory to decide on a deficiency state. Recently, holotranscobalamin (holoTC) has been proposed as a useful alternative indicator of vitamin B12 status, however studies on its value in diagnosing cobalamin deficiency have not come to a conclusion yet. The purpose of this study is to investigate the usefulness of holoTC measurement together with total vitamin B12 measurement in diagnosing cobalamin deficiency, in a cross-sectional analysis. Material and Method: Four hundred volunteers were grouped according to vitamin B12 levels as vitamin B12 deficient (vit B12<193 pg/ml, n=168), borderline (vit B12<193-300 pg/ml, n=100) and controls (vit B12>300 pg/ml, n=132). These groups were divided into two subgroups (A and B) according to holoTC cut-off value (35 pmol/L). The diagnostic efficacy of vitamin B12, holoTC and a combination of both measures were evaluated. Serum folate and homocysteine (Hcy) were used as indicators of vitamin B12 deficiency. Results: Significantly higher Hcy and lower folate levels were observed in both vitamin B12 deficient and borderline B12 groups provided that holoTC levels were low. Conclusion: Evaluation of vitamin B12 measures together with holoTC measures provides a more accurate diagnosis, especially in patients with borderline-B12 concentrations.