Prevalence of Vitamin B12 Deficiency and its associated Factors among Patients with Type 2 Diabetes Mellitus on Metformin from a District in Malaysia

  • Gayathri Devi Krishnan Hospital Raja Perempuan Zainab II, Kota Bjaru, Kelantan
  • Miza Hiryanti Zakaria Hospital Tengku Ampuan Afzan, Kuantan, Pahang
  • Norhayati Yahaya Hospital Raja Perempuan Zainab II, Kota Bharu, Kelantan
Keywords: Vitamin B12, metformin, deficiency, type 2 diabetes mellitus, type 2 DM


Introduction. Vitamin B12 deficiency is more common among metformin-treated subjects although the prevalence is variable. Many factors have been associated with this. The aim of this study is to determine the prevalence of vitamin B12 deficiency and its associated factors among patients with type 2 diabetes mellitus (DM) who are on metformin.

Methodology. A total of 205 patients who fit eligibility criteria were included in the study. A questionnaire was completed, and blood was drawn to study vitamin B12 levels. Vitamin B12 deficiency was defined as serum B12 level of  ≤300 pg/mL (221 pmol/L).

Results. The prevalence of vitamin B12 deficiency among metformin-treated patients with type 2 DM patients was 28.3% (n=58). The median vitamin B12 level was 419 (±257 ) pg/mL. The non-Malay population was at a higher risk for metformin-associated vitamin B12 deficiency [adjusted odds ratio (OR) 3.86, 95% CI: 1.836 to 8.104, p<0.001]. Duration of metformin use of more than five years showed increased risk for metformin-associated vitamin B12 deficiency (adjusted OR 2.06, 95% CI: 1.003 to 4.227, p=0.049).

Conclusion. Our study suggests that the prevalence of vitamin B12 deficiency among patients with type 2 diabetes mellitus on metformin in our population is substantial. This is more frequent among the non-Malay population and those who have been on metformin for more than five years.


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Author Biography

Gayathri Devi Krishnan, Hospital Raja Perempuan Zainab II, Kota Bjaru, Kelantan

Clinical Specialist, Fellow in Endocrinology

Ministry of Health, Malaysia


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How to Cite
Krishnan, G. D., Zakaria, M. H., & Yahaya, N. (2020). Prevalence of Vitamin B12 Deficiency and its associated Factors among Patients with Type 2 Diabetes Mellitus on Metformin from a District in Malaysia. Journal of the ASEAN Federation of Endocrine Societies, 35(2). Retrieved from
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