Abstract: Objective: To investigate the changes in vitamin levels in middle aged and elderly patients with diabetes mellitus in Shanghai. Methods: A total of 1 100 middle aged and elderly participants undergone health examination were enrolled during January 2016 to November 2016. Of these participants, 264 diabetic patients were categorized into the diabetic group and the other 836 non-diabetes were served as the control group. All the subjects were tested for vitamins (vitamin A, B₁, B₂, B₆, B₁₂, C, E and folic acid) and glycosylated hemoglobin (HbA1c), and differences in vitamin levels between diabetic group and control group were compared. According to the level of glycosylated hemoglobin (HbA1c), patients with type 2 diabetes mellitus were further divided into 2 groups: well-controlled group(HbA1c<7.0%) and poor-controlled group (HbA1c≥7.0%). The correlation of HbA1c with vitamins in the body was assessed. Results: Compared with controls, diabetes mellitus patients had a lower serum vitamin B₁₂ level [(408.82±163.53) pg/mL vs (437.49±206.82) pg/mL P<0.05]. Patients with HbA1c≥7.0% had lower level of vitamin B₁₂ than patients with HbA1c<7.0%[(372.89±129.68) pg/mL vs(422.30±172.92) pg/mL, P<0.05]. Linear correlation analysis showed that level of glycated hemoglobin had no correlation with serum levels of other vitamins (all P>0.05). Conclusions: Compared with non-diabetes, patients with diabetes have lower serum vitamin B₁₂ level, and poor controlled diabetic patients have lower serum vitamin B₁₂ level than well-controlled diabetic patients.

Key words: Diabetes mellitus, Vitamins, Glycosylated hemoglobin