A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial of High-Dose, Short-Term Vitamin D Administration in the Prevention of Acute Kidney Injury after Cardiac Surgery

Abstract

<b><i>Background:</i></b> Acute kidney injury (AKI) after cardiac surgery is a relatively common complication affecting short- and long-term survival. The renoprotective effect of vitamin D (VitD) has been confirmed in several experimental models. This study was conducted to evaluate the effect of high-dose VitD administration in patients with VitD insufficiency on the incidence of postoperative AKI, the urinary level of tubular biomarkers, and serum anti-inflammatory biomarker after coronary artery bypass graft. <b><i>Design and Method:</i></b> In this randomized double-blind controlled clinical trial, the patients were randomly allocated to either the VitD group (<i>n</i> = 50), receiving 150,000 IU VitD tablets daily for 3 consecutive days before surgery or the control group (<i>n</i> = 61), receiving placebo tablets. <b><i>Results:</i></b> There was no difference in the incidence of postoperative AKI between the groups. Both of the urinary levels of interleukin-18 and kidney injury molecule-1 were significantly increased after the operation (<i>p</i> < 0.001, for both). Also, the serum level of interleukin-10 was increased after 3 days of VitD supplementation (<i>p</i> = 0.001). In comparison with the control group, it remained on a higher level after the operation (<i>p</i> < 0.001) and the next day (<i>p</i> = 0.03). The patients with AKI had more postoperative bleeding and received more blood transfusion. <b><i>Conclusion:</i></b> VitD pretreatment was unable to impose any changes in the incidence of AKI and the urinary level of renal biomarkers. However, high-dose administration of VitD may improve the anti-inflammatory state before and after the operation. Further studies are needed to assess the renoprotective effect of VitD on coronary surgery patients.

Effect of Vitamin D Supplementation on Postoperative Outcomes in Cardiac Surgery Patients: A Systematic Review

“…9 One study (12.5%) detected small reduction of interleukin-10 in vitamin D supplementation group compared with placebo without any difference in postoperative acute kidney injury. 12 One study (12.5%) observed anti- inflammatory effect with high-dose supplementation but without any difference in prevention of acute kidney injury both in control and treatment group. 12 There was an insignificant lesser incidence of adverse cardiac events like pacemaker insertion and cardiomyopathy, POAF, and postoperative heart failure with vitamin D supplementation in one RCT.…”

“…12 One study (12.5%) observed anti- inflammatory effect with high-dose supplementation but without any difference in prevention of acute kidney injury both in control and treatment group. 12 There was an insignificant lesser incidence of adverse cardiac events like pacemaker insertion and cardiomyopathy, POAF, and postoperative heart failure with vitamin D supplementation in one RCT. 7 All the eight RCT did not found any adverse effects with vitamin D supplementation and detected to be safe in all patients even with high doses.…”

Role of vitamin D supplementation in modifying outcomes after surgery: a systematic review of randomised controlled trials

“…However, no significant differences were observed for the other complications that they considered, including myocardial infarction (p=0.831) and severe bleeding (p=0.653). Other studies assessed serious adverse events, 24 acute kidney injury, 31 acute respiratory distress syndrome 23 and patient-important complications, 25 all of which reported rates to be similar in the vitamin D and control groups, with no significant differences detected.…”

Vitamin D Supplementation Has No Impact on Cardiorespiratory Fitness, but Improves Inflammatory Status in Vitamin D Deficient Young Men Engaged in Resistance Training

“…Calcitriol, the bioactive form of Vit-D, inhibits and stimulates the production of pro-and anti-inflammatory cytokines, respectively, [3,35,36] and Vit-D supplementation in healthy adults, depending on dose, has analogous impact on cytokine production in monocyte-derived macrophages [37]. Different Vit-D supplementation regimens [38][39][40], resistance training (RT) [41,42], or Vit-D supplementation in combination with RT [39,43] show anti-inflammatory effects in patients suffering under various diseases characterized by high level chronic inflammation. According to Forti et al [44] and Ihalainen et al [45], suppression of chronic inflammation at a young age can be an effective measure to prevent or delay the onset of inflammation and related diseases later in life, and they have demonstrated anti-inflammatory effects of various RT programs in young healthy adults.…”