Main Article Content
Objective: Type 2 diabetes (T2DM) disease and related changes in blood parameters bring essential health risks. This study was carried out to determine the frequency of vitamin B12 deficiency in T2DM patients, the effect of B12 deficiency on blood glucose, HbA1c control and lipid parameters, and the B12 level in diabetes patients using metformin.
Material and Methods: 287 patients with T2DM who were followed up in the Endocrinology department of Istanbul Training and Research Hospital were evaluated. After the patients called for control had fasted for 8 hours, blood tests were performed, and biochemical parameters were determined with standard laboratory techniques. Vitamin B12 <180 mg/dl was accepted as a deficiency, and patients were divided into groups regarding vitamin B12 deficiency. The chemiluminescence method was used to determine serum Vitamin B12 levels. Data were analyzed using SPSS version 22.0 (IBM Corporation, Armonk, NY, USA).
Results: A total of 287 T2DM patients were included in the study. B12 deficiency is present in 29.8% of T2DM patients. Vitamin B12 values were found to be lower in patients with T2DM using metformin (280.2 pg /ml ±151.06 pg/ml, p<0.05); however, lower vitamin B12 values did not have a significant effect on blood sugar control (p=0,3), and hypovitaminosis Vitamin B12 was associated with elevated hypertriglyceridemia (p=0,03).
Conclusion: According to the current study, serum vitamin B12 level was not associated with blood glucose and HbA1c; a relationship was found between vitamin B12 deficiency and higher hypertriglyceridemia. A significant proportion of T2DM patients using metformin had lower levels of vitamin B12 compared to T2DM patients not using metformin. Vitamin B12 levels should be monitored regularly in the follow-up of patients with T2DM using metformin.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Adler AI. Association of systolic blood pressure with macrovascular and microvascular complications of type 2 diabetes (UKPDS 36): prospective observational study. BMJ [Internet]. 2000;321:412–9. doi: 10.1136/bmj.321.7258.412. [PMC free article] [PubMed] [CrossRef] [Google Schol
Liu W, Luo Z, Zhou J, Sun B. Gut Microbiota and Antidiabetic Drugs: Perspectives of Personalized Treatment in Type 2 Diabetes Mellitus. Front Cell Infect Microbiol. 2022 May 3 1;12:853771. doi: 10.3389/fcimb.2022.853771. PMID: 35711668; PMCID: PMC9194476.
Le Y, Wang B, Xue M. Nutraceuticals use and type 2 diabetes mellitus. Curr Opin Pharmacol. 2022 Feb;62:168-176. doi: 10.1016/j.coph.2021.12.004. Epub 2022 Jan 20. PMID: 35066463.
Alhaji JH. Vitamin B12 Deficiency in Patients with Diabetes on Metformin: Arab Countries. Nutrients. 2022 May 13;14(10):2046. doi: 10.3390/nu14102046. PMID: 35631186; PMCID: PMC9144422.
American Diabetes Association. 2. Classification and diagnosis of diabetes: standards of medical care in diabetes-2020. Diabetes Care 2020; 43(Suppl1): S14–S31.
Hidong Kim, Emma P. Deloughery, Alicia Algeciras-Schimnich, Neeraj Kumar, Rajiv K. Pruthi, Measurement of Vitamin B12 and Serum Methylmalonic Acid Levels: Role of Stepwise Cascade Testing in Diagnosing Vitamin B12 Deficiency, Blood, Volume 132, Supplement 1, 2018, Page 4688.
Al-Hamdi A, Al-Gahhafi M, Al-Roshdi S, Jaju S, Al-Mamari A, Al Mahrezi AM. Vitamin B12 Deficiency in Diabetic Patients on Metformin Therapy: A cross-sectional study from Oman. Sultan Qaboos Univ Med J. 2020 Feb;20(1):e90-e94. doi: 10.18295/squmj.2020.20.01.013. Epub 2020 Mar 9. PMID: 32190375; PMCID: PMC7065694.
Krishnan GD, Zakaria MH, Yahaya N. Prevalence of Vitamin B12 Deficiency and its Associated Factors among Patients with Type 2 Diabetes Mellitus on Metformin from a District in Malaysia. J ASEAN Fed Endocr Soc. 2020;35(2):163-168.
Hvas AM, Nexo E. Diagnosis and treatment of vitamin B12 deficiency--an update. Haematologica. 2006 Nov;91(11):1506-12. Epub 2006 Oct 17. PMID: 17043022.
Reinstatler L, Qi YP, Williamson RS, Garn JV, Oakley GP Jr. Association of biochemical B12 deficiency with metformin therapy and vitamin B12 supplements: the National Health and Nutrition Examination Survey, 1999-2006. Diabetes Care. 2012;35:327-33.
Ting RZ-W, Szeto CC, Chan MH-M, Ma KK, Chow KM. Risk factors of vitamin B(12) deficiency in patients receiving metformin. Arch. Intern. Med. 2006;166:1975-9.
de Groot-Kamphuis DM, van Dijk PR, Groenier KH, Houweling ST, Bilo HJ, Kleefstra N. Vitamin B12 deficiency and the lack of its consequences in type 2 diabetes patients using metformin. Neth J Med. 2013 Sep;71(7):386-90. PMID: 24038568.
Wasilewska A, Narkiewicz M, Rutkowski B, Lysiak-Szydlowska W. Is there any relationship between lipids and vitamin B levels in persons with elevated risk of atherosclerosis? Med Sci Monit. 2003;9(3):CR147–CR151.
Increased intake of calcium reverses vitamin B12 malabsorption induced by metformin. Diabetes Care 2000; 23: 1227–1231.
Bell DSH. Metformin-induced vitamin B12 deficiency can cause or worsen distal symmetrical, autonomic and cardiac neuropathy in the patient with diabetes. Diabetes Obes Metab. 2022 Aug;24(8):1423-1428. doi: 10.1111/dom.14734. Epub 2022 May 20. PMID: 35491956.
Pratama S, Lauren BC, Wisnu W. The efficacy of vitamin B12 supplementation for treating vitamin B12 deficiency and peripheral neuropathy in metformin-treated type 2 diabetes mellitus patients: A systematic review. Diabetes Metab Syndr. 2022 Oct;16(10):102634.
Brindle NP, Zammit VA, Pogson CI. Regulation of carnitine palmitoyltransferase activity by malonyl-CoA in mitochondria from sheep liver, a tissue with a low capacity for fatty acid synthesis. Biochem J. 1985;232(1):177–182.
Li W, Zhao J, Zhu LL, Peng YF. Serum vitamin B12 levels and glycemic fluctuation in patients with type 2 diabetes mellitus. Ther Adv Endocrinol Metab. 2022 Jun 1;13:20420188221102800.
Obeid R, Shannan B, Herrmann W. Advanced glycation end products overload might explain intracellular cobalamin deficiency in renal dysfunction, diabetes and aging. Med Hypotheses 2011; 77: 884–888.
Xiong S, Liu Z, Yao N, Zhang X, Ge Q. The independent association between vitamin B12 and insomnia in Chinese patients with type 2 diabetes mellitus: a cross-sectional study. Nutr Diabetes. 2022 Jan 17;12(1):3. doi: 10.1038/s41387-022-00181-8. PMID: 35039481; PMCID: PMC8764026.