Vitamin B12 deficiency and the knowledge and practice of physicians regarding screening for vitamin B12 deficiency among type 2 diabetic patients on metformin in selected hospitals in Riyadh, Saudi Arabia

BACKGROUND/AIM: The worldwide prevalence of diabetes is high including Saudi Arabia. One standard first-line treatment for diabetes is metformin, which was reported to increase the risk for vitamin B12 deficiency. We wanted to determine the prevalence of vitamin B12 deficiency in metformin-treated type 2 diabetes mellitus patients. METHODS: We conducted a cross-sectional study at the diabetic clinics of four hospitals in Riyadh, Saudi Arabia. Type 2 diabetes mellitus patients who were on metformin for at least 1 year were included in the study. Associations between B12 deficiency and age, duration of type 2 diabetes mellitus (T2DM), duration of use and dosage of metformin, and use of proton pump inhibitors (PPIs) were determined. RESULTS: Of 363 T2DM patients, 206 (56.7%) were males and 157 (43.3%) were females, mean age was 53.72 ± 11.31 years, the mean duration of T2DM was 9.89 ± 7.32 years, and the mean duration of metformin use was 9.84 ± 7.29 years. There were 205 patients 56.5% who had a daily dose of 750 mg of metformin. The most commonly used oral hypoglycemic agent was gliclizide only in 138 (38.4%) of patients. There were 107 patients (29.5%) who were on PPIs. There were 210 patients (57.9%) who were on vitamin B12 supplementation, of which 111 (30.6%) had a daily dose of 200 mcg. The use of vitamin B12 supplement, duration of T2DM and duration of metformin use was significantly higher among females. The use of vitamin B12 supplement was significant among patients who were 46 years old and above. There were only 16 patients (4.4%) who had available serum vitamin B12 levels. Only 44.0% of the physician respondents know the current recommendation of American Diabetes Association on vitamin B12 screening and supplementation among diabetic patients, and 21.0% never prescribe vitamin B12 to their patients. CONCLUSION: Routine testing for serum vitamin B12 level is not practiced in our institution. A large percentage of physicians are not aware of the current recommendations of the American Diabetic Association (ADA) regarding vitamin B12 supplementation and screening. Thus, there is a need for doctors involved in the management of diabetes to keep abreast with guidelines and current recommendations and routinely monitor vitamin B12 levels particularly those who were on long-term takers of metformin and the elderly patients to optimize management of diabetes and its complications.