The Effect of Metformin Therapy on Vitamin D and B12 Levels in Patients with Diabetes Mellitus Type 2
Endocrine Practice, 09/26/2011
Kos E et al. – This study confirms the higher prevalence of vitamin B12 deficiency in metformin treated type 2 diabetic patients. This study also suggests that vitamin D deficiency is not a clinical concern among metformin treated type 2 diabetics, and metformin does not negatively impact treatment of vitamin D deficiency in these patients.Methods
- This is a retrospective chart review of patients treated between 2003–2009 at Loyola University Medical Center in both ambulatory primary care and endocrinology clinics.
- 706 patients aged 20–93 with diabetes mellitus type 2 were included with a mean age of 63 ± 13 years and a mean BMI of 33.1 kg/m2.
- 34% of these patients used metformin, and 35% of these patients had been diagnosed with osteoporosis/osteopenia.
- Patients on metformin had statistically significant lower vitamin B12 levels than those not on metformin (p<0.0001, 95% CI = (–220, –84)).
- No statistically significant difference was shown between users and nonusers of metformin in regard to vitamin D levels when adjusted for variables (p=0.297, 95% CI for mean difference = (–0.7, 2.2)).
- Metformin use did not adversely affect successful treatment of vitamin D deficiency in this population as a whole, nor did it affect the subgroup with osteoporosis (p =0.956).
- Those with osteoporosis did have statistically significant lower baseline vitamin D levels compared to those without when adjusted for all variables (p=0.002, 95% CI = (0.8, 3.9)).