To estimate the prevalence of Vitamin B12 deficiency among patients with diabetes.

This cross-sectional study was undertaken on 351 patients with diabetes at a specialised public diabetes clinic in Gaborone between July 2017 and October 2017. Clinical, anthropometry and laboratory data were collected. Vitamin B12 deficiency was defined by levels < 150 pmol/l.

The mean (SD) age of the participants was 57 (15) years, two-thirds (67.2%) were females, and the majority (92.9%) had Type 2 diabetes. Most (89.5%) participants were on metformin. The prevalence of vitamin B12 deficiency was 6.6%. Compared with participants with normal Vitamin B12 levels, deficient participants were significantly older (64 vs. 56 years, p = 0.014) and had a longer duration of metformin use (7 vs. 4 years, p = 0.024). The use of acid blockers was also associated with vitamin B12 deficiency (p = 0.012). There was no difference in the prevalence of peripheral neuropathy between those with normal and deficient vitamin B12 levels.

Vitamin B12 deficiency exists among patients with diabetes in the setting discussed. Regular vitamin B12 assessment may be beneficial, especially among diabetes patients who are old, those taking metformin over a long duration and patients on acid blockers.