Study Shows Vitamin B12 Deficiency Often Occurs in Long-Term Metformin Users

Metformin intake of Type 2 diabetes mellitus patients is being observed by researchers due to its side effects. Frequent doses of metformin can result in vitamin b12 deficiency. Diabetes patients are often exposed to metformin, as it is an oral medication for hyperglycemia. Metformin can regulate high blood sugar, which aids in preventing kidney damage, blindness, nerve problems, loss of limbs, and sexual function difficulties. The medication also restores the proper insulin response of the patient’s body.

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Although a first-line treatment, alternative medications are also formulated for specific individuals. It depends on the patient’s situation and characteristics. The first side effect of Metformin discovered was the temporary occurrence of gastrointestinal disturbance. Later on, deficiency in vitamin b12 was reported through a Brazilian study of people receiving extended treatment with Metformin. The result ranged from 5.8% to 30% of the patients who were observed in the study.

To gather further concrete evidence that oral medication affects vitamin B12 in the body, scientists conducted research in a tertiary care hospital in Pakistan. Pakistan has a prevalence record of type 2 diabetes that ranges from 7.2% to 19.21%. The study’s authors are Fraz Ahmed Baig, Saad Khan, and Amber Rizwan. They assessed patients diagnosed with Type 2 DM from February 2021 to December 2021. Another control group was involved in the study, which consisted of 100 patients without records of diabetes.

The patients included in the control groups were all approved by the ethical review board of Jinnah Sindh Medical University. After receiving approval, they were all enrolled in the outpatient department of internal medicine. The study was done with full consent from the patients, and all recorded data have secured privacy. The participants’ blood samples were submitted to a laboratory for examination. To distinguish deficiency in Vitamin B12, the participants’ blood samples must have a result of less than 200pg/mL serum levels. Vitamin B12 was measured through competitive-binding immunoenzymatic assays by a Unicel DxI 800 analyzer (Beckman Coulter, Inc., Brea, USA).

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According to the journal published in Cureus, the mean and standard deviation were evaluated for the age and serum B12 values. Upon reading the results, researchers concluded that non-diabetic participants have higher serum vitamin B12 levels compared to diabetes patients. A more significant value of hypovitaminosis was found in the blood samples of diabetic participants.

All results led to one conclusion, and that is the evident effects of metformin on vitamin B12. The investigation proved that an increase in time on metformin can cause vitamin B12 deficiency. High-level studies backed up the investigation, as it was included in a treatment guideline from the 2017 American Diabetes Association. It was stated that vitamin B12 in patients using metformin should be regularly checked. The primary authors of the study explained that the role of metformin in decreasing vitamin B12 levels is because it hinders the smooth functioning of the calcium-regulated membrane that absorbs the vitamin in the ileum.

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