The Journal of the American Medical Association published a randomized controlled trial on April 28, 2010 that found the administration of B-vitamins failed to slow the progression of diabetic nephropathy and was associated with an increase in vascular events. The trial was stopped early for safety reasons.1
Patients included in the study had type 1 or type 2 diabetes and a clinical diagnosis of diabetic nephropathy with albuminuria or proteinuria. Trial subjects were assigned to receive B vitamin supplementation with vitamin B6 - 25 mg, vitamin B12 -1 mg, folic acid - 2.5 mg daily or a matching placebo.
The glomerular filtration rate (GFR) decreased by a mean of 16.5 mL/min/1.73 m2 in the vitamin B group compared to 10.7 mL/min/1.73 m2 in placebo group. There was a statistically significant increase in the secondary outcome of the composite endpoint of myocardial infarction (MI), stroke, revascularization, and all cause motility in the vitamin B group compared to placebo (2.0 [95% CI, 1.0 – 4.0], p = 0.04). Plasmin homocysteine levels decreased in the B vitamin group and were increased in those receiving placebo.
Overall, in patients with diabetic nephropathy and stages 1 to 3 chronic kidney disease, the use of B vitamins compared to placebo resulted in a greater decrease in kidney function an increase in vascular events.
The National Drug and Poison Information Center (NDPIC) in Saudi Food And Drug Authority is aware that at some clinics and medical centers, B vitamins are being prescribed or recommended for patients with diabetic nephropathy. In light of these new findings the NDPIC is urging centers and clinicians to reevaluate the use of B vitamins as homocysteine-lowering agents in patients with diabetic nephropathy.
1. House AA, Eliasziw M, Cattran DC et al. Effect of B-vitamin therapy on progression of diabetic nephropathy: a randomized controlled trial. JAMA 2010;303(16):1603-1609.