Vitamin D receptor activation with paricalcitol decreases albuminuria in type 2 diabetes

Vitamin D is a steroid hormone and a component of a complex endocrine pathway sometimes called 'vitamin D endocrine system' (Medscape, 2012).  Despite treatment with renin—angiotensin—aldosterone system (RAAS) inhibitors, patients with diabetes have increased risk of progressive renal failure that correlates with albuminuria.

281 patients with type 2 diabetes and albuminuria who were receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers were enrolled in this study.

Patients were assigned to receive 24 weeks' treatment with:

- placebo
- 1 μg/day paricalcitol
- 2 μg/day paricalcitol

Paricalcitol (trade name Zemplar, Abbott Laboratories) is an analog of calcitriol, the active form of vitamin D.

The primary endpoint was the percentage change in mean urinary albumin-to-creatinine ratio (UACR).

The change in urinary albumin-to-creatinine ratio (UACR) was: −14% in the 1 μg paricalcitol group, and −20% in the 2 μg paricalcitol group.

The addition of 2 μg/day paricalcitol to RAAS inhibition safely lowers albuminuria in patients with diabetic nephropathy, and could be a novel approach to lower renal risk in diabetes.

References:
Selective vitamin D receptor activation with paricalcitol for reduction of albuminuria in patients with type 2 diabetes (VITAL study): a randomised controlled trial. The Lancet, Volume 376, Issue 9752, Pages 1543 - 1551, 6 November 2010.

Image source: Paricalcitol, Wikipedia, public domain.