About 40% of people with diabetes will develop kidney disease (diabetic nephropathy); 44% of cases of renal failure are linked to diabetes.B vitamins lower blood homocysteine levels, high levels of which are thought to raise the risk for diabetic nephropathy.
Can taking B vitamins lower the risk of kidney disease among diabetics? Researchers from Canada set out to answer that question:
Effect Of B-Vitamin Therapy On Progression Of Diabetic Nephropathy, Journal of the American medical Association, April 2010
They reported that people with diabetes and nephropathy who took supplemental vitamin B had a greater decline in kidney function than those taking placebo. Supplementers also had a higher rate of heart attack and stroke.
Patients took a tablet containing placebo or:
- Folic acid (2.5 mg/d)
- Vitamin B6 (25 mg/d)
- Vitamin B12 (1 mg/d)
- Folic acid (400 mcg/d = 0.4 mg/d)
- Vitamin B6 (1.3 to 1.7 mg/d)
- Vitamin B12 (2 to 3 mcg/d = .002 to .003 mg/d)
Not only was the folic acid/B6/B12 blend not helpful, it likely did harm.
Science Daily has a good summary:
High Doses of B Vitamins Associated With Increased Decline in Kidney Function for Patients With Kidney Disease from Diabetes
