Effect of Vitamin D therapy on urinary albumin excretion, renal functions, and plasma renin among patients with diabetic nephropathy

Abstract

Background:Despite different management strategies, progression of proteinuria occurs in a sizable category of patients with diabetic nephropathy (DN). Increase in serum renin levels induced by the renin–angiotensin system (RAS) may contribute to this. Vitamin D therapy is found to have an inhibitory effect on the RAS. We aimed to study the effects of Vitamin D therapy on renal functions of patients with DN.Methods:This was a double-blind, randomized, placebo-controlled study. Patients with DN (urinary albumin [UA] >30 mg/g of creatinine) whose estimated glomerular filtration rate (eGFR) was more than 30 mL/min were selected and their plasma renin, parathyroid hormone, serum Vitamin D, serum calcium, serum creatinine, fasting blood sugar were done as baseline measurements. Subjects were randomized into two groups and treatment group was given Vitamin D, 50000 IU (0.25 ml) intramuscularly (IM) monthly for 6 months; control group received distilled water IM. Investigations were repeated after 6 months of therapy.Results:Of 155 patients invited, 85 were randomly assigned to two groups. After 6 months, mean reduction of UA to creatinine ratio in the treatment and control group was 51.8 mg/g (95% confidence interval [CI]; 66.1–−37.5, P ≤ 0.001); 22.4 mg/g (95% CI; −45.7–0.8, P = 0.06), respectively (between group difference P = 0.001). Significant increase in the eGFR observed in the treatment group while eGFR remained unchanged in the control group (P = 0.03 for the between-group difference). Mean reduction in plasma renin in treatment group and control group was 5.85 pg/mL (95% CI; −6.7–−4.6) (P < 0.001) and 0.95 pg/mL (95% CI; −1.4–−0.14, P = 0.02), respectively.Conclusions:Vitamin D 50000 IU given IM monthly for 6 months reduces urine albumin, serum creatinine, and renin levels in patients with DN.

Vitamin D in diabetic nephropathy

“…[ 8 ] In addition, proposed pleiotropic benefits were not observed. Intriguingly, in the current study,[ 9 ] supranormal levels of vitamin D were achieved without adverse effects. Thus, appropriate dosage of vitamin D remains uncertain.…”

Effect of vitamin D on proteinuria, lipid status, glicoregulation and C-reactive protein in patients with type-2 diabetes mellitus

“…Proteinuria is the main target to treat in order to prevent and slow down DN and decrease incidence of cardiovascular events 20,21,24 . Vitamin D decreases proteinuria by RAAS inhibition and reduces renal fibrosis by reduction of TGFβ/SMAD pathway [15][16][17] . Vitamin D, apart of renal RASS inhibition, reduces renin expression in heart thereby decreasing arterial blood pressure 20,21 .…”

“…Proteinuria seems to be the most important target to treat in order to prevent cardiovascular events in patients with DN and CKD 13,14,17,20,21 . Paricalcitol and cholecalciferol can decrease proteinuria in patients with CKD or DM [22][23][24][25] .…”

“…Vitamin D is essential hormone obtained from food (10%-20%) and skin synthesis. Apart from its primary role on calcium and phosphorus homeostasis, it is believed that vitamin D has certain renoprotective effect, antifibrotic, antiinflammatory effect, inhibits renin angiotensin aldosterone system (RAAS), role in maintaining cardiomyocyte health and insulin sensitivity and role in reducing albuminuria in patients with CKD and DM [13][14][15][16][17] . 13,14 .…”

Impact of Vitamin D Receptor Gene Polymorphism on Chronic Renal Failure Susceptibility

“…It is well known that vitamin D is a central regulator to control bone and calcium metabolism. Lots of evidence suggested that vitamin D is involved in various renal diseases . Recent research found that a reduced level of vitamin D among CRF patients with and without dialysis, and vitamin D deficiency was associated with vascular calcification, anemia, and cardiovascular mortality in ESRD patients .…”