Back to Journals » Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy » Volume 10

Do we need to measure vitamin B12 and magnesium in morbidly obese patients with type 2 diabetes mellitus?

Authors Wåhlén A, Haenni A, Johansson HE

Received 30 December 2016

Accepted for publication 23 March 2017

Published 2 May 2017 Volume 2017:10 Pages 151—154


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 4

Editor who approved publication: Professor Ming-Hui Zou

Anna Wåhlén,1 Arvo Haenni,2,3 Hans-Erik Johansson1–3

1Östervåla Primary Health Care Centre, Östervåla, 2Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala, 3Skönvikt, Outpatient Clinic of Obesity Care, Säter, Sweden

Objective: We aimed to investigate the prevalence of B12 deficiency in metformin-treated, morbidly obese, type 2 diabetes mellitus (T2DM) patients, compared to morbidly obese controls, as well as to evaluate the magnesium status.
Retrospective cross-sectional analysis of plasma vitamin B12, plasma magnesium, glucometabolic status and clinical measurements in all consecutive morbidly obese patients was conducted during 1 year.
Outpatient Clinic of Obesity Care.
Subjects: One hundred forty-seven patients were evaluated: 107 morbidly obese controls and 40 metformin-treated, morbidly obese patients with T2DM.
Main outcome measures: Circulating plasma concentrations of vitamin B12 (cobalamin), magnesium, clinical measurements and metformin medication.
Results: There were differences between the two groups regarding age, sagittal diameter, glucose parameters and magnesium concentrations. Longer diabetes duration was associated with lower magnesium. Metformin-treated T2DM patients had lower magnesium (0.76±0.07 mmol/L) than controls (0.82±0.07 mmol/L). A subgroup analysis of 26 non-metformin-treated T2DM patients showed a normal magnesium concentration compared to controls, that is, 0.81±0.06 mmol/L. We found no statistical difference in B12 concentrations between the two groups.
Conclusion: To fully benefit from metformin medication, routine testing of B12 as well as magnesium in metformin-treated, morbidly obese patients should be performed, with consideration of substitution to avoid low levels.

Keywords: metformin medication, vitamin B12, magnesium, type 2 diabetes mellitus, morbidly obese

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]