Research published in Diabetologia (2009 Feb;52(2):208–12) examined whether thiamin (vitamin B1) supplementation could help protect kidney function in people with type 2 diabetes.
Microalbuminuria—small amounts of protein leaking into the urine—is an early warning sign of diabetic kidney damage.

In this randomized, placebo-controlled study, 40 adults with type 2 diabetes and microalbuminuria were divided into two groups. For three months:

  • One group received 100 mg of thiamin three times per day

  • The other group received a placebo

At the end of the study, the thiamin group experienced an average 41% reduction in urinary albumin, indicating improved kidney function compared to the placebo group.