Vitamin B12 Monitoring in Metformin Users: Are We Missing an Opportunity for Safer Diabetes Care?
Recommended Citation
Pierce L, Lee P, Pham L, Polina S, Wehbi D. Vitamin B12 Monitoring in Metformin Users: Are We Missing an Opportunity for Safer Diabetes Care?. Am J Health Syst Pharm 2026; 83:S801.
Document Type
Conference Proceeding
Publication Date
3-6-2026
Publication Title
Am J Health Syst Pharm
Keywords
Pharmacology & Pharmacy
Abstract
Purpose: Metformin is a commonly prescribed medication for type 2 diabetes mellitus (T2DM) management associated with reduced intestinal absorption of vitamin B12, particularly in patients undergoing long-term treatment. Although the American Diabetes Association (ADA) guidelines recommend annual vitamin B12 testing in patients on metformin therapy for at least 4 years, real-world practice patterns vary, and many health systems lack standardized screening recommendations. This study aims to evaluate provider practices for monitoring vitamin B12 levels and identify prescribing practices of vitamin B12 supplementation. These findings will guide decisions on whether implementing standardized screening and supplementation protocols are valuable for large health systems. Methods: This is an institutional review board approved, retrospective, descriptive study that will examine the relationship between metformin use and vitamin B12 deficiency in patients with T2DM. This study will assess adult patients seen by a legacy Henry Ford Health primary care provider (PCP) between September 1st, 2023, to September 1st, 2024, and has been on metformin therapy for at least 4 years. Vulnerable patients and those diagnosed with vitamin B12 deficiency or other comorbidities related to vitamin B12 deficiencies (i.e., alcoholism, gastric bypass, GERD) will be excluded. The primary endpoint is the percentage of patients who had vitamin B12 levels checked within a 12-month period of their last PCP visit. Notable secondary endpoints will include percentage of patients who had low vitamin B12 levels (< 200 pg/mL) and borderline vitamin B12 levels (200-300 pg/mL), percentage of patients who had vitamin B12 levels checked by a provider other than their PCP, percentage of patients being treated for vitamin B12 deficiency, and types of vitamin B12 supplement treatments. Data collection will include baseline patient demographics, date of PCP visit, duration of T2DM diagnosis, duration of metformin use, serum vitamin B12 levels with date of tests, type of B12 supplementation, and when treatment was initiated. The data will be analyzed using descriptive statistics.
Volume
83
First Page
S801
