Vitamin B 12 and folic acid serum levels in diabetics under various therapeutic regimens.
The aim of the present study was to reconsider the problem of the haematological consequences of biguanide treatment by evaluating serum vitamin B 12 and folic acid levels as well as classical haematological parameters in 30 diabetics treated by metformin. For purpose of comparison, similar evaluations were done in diabetics treated with insulin (27 patients) or sulfonylureas (13 patients). Results indicated that mean serum levels of vitamin B 12 were significantly lower in patients receiving metformin than in both other groups. In the metformin-treated group, five patients had serum levels of vitamin B 12 below 270 pg/ml and five had borderline values. No difference was found in the mean serum folic acid levels between the three groups. Similarly, there were no differences in the red blood cell counts, volumes or haemoglogin concentrations nor in the mean values of serum iron and lacticodeshydrogenase levels between the three groups. Since the haematologic and neurologic complications of vitamin B 12 deficiency may only appear after the deficiency had existed for 10-15 years, the lack of haematological alteration may be explained by the fact that the vitamin B 12 deficiency was not present for a sufficient period of time. We conclude that it may be wise to monitor the haematological values as well as vitamin B 12 levels at regular intervals in diabetic patients treated with metformin so that B 12 hypovitaminosis and its complications can be prevented.
D003920:Diabetes Mellitus / Q000097:blood / Q000188:drug therapy*; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000627:therapeutic use; D007501:Iron / Q000097:blood; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D013453:Sulfonylurea Compounds / Q000627:therapeutic use; D014805:Vitamin B 12 / Q000097:blood*
D007328:Insulin; D013453:Sulfonylurea Compounds; D008687:Metformin; D005492:Folic Acid; D007501:Iron; D007770:L-Lactate Dehydrogenase; D014805:Vitamin B 12