Impact of Ergocalciferol Treatment of Vitamin D Deficiency on Serum Parathyroid Hormone Concentrations in Chronic Kidney Disease

Abstract

Background: Vitamin D deficiency is highly prevalent and associated with secondary hyperparathyroidism in patients with chronic kidney disease (CKD). The Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines recommend treatment of vitamin D deficiency starting with CKD stage 3, though no data are available showing an impact on serum parathyroid hormone (PTH) concentrations. The goal of this analysis, therefore, was to determine the effect of ergocalciferol treatment on plasma PTH concentrations in vitamin D-deficient patients with stage 3 and stage 4 CKD. Methods: A prospective, nonrandomized observational analysis was conducted in an academic community hospital CKD clinic. Fifty-two patients with stage 3 or stage 4 CKD with vitamin D deficiency and elevated PTH concentrations received ergocalciferol dosed per a modified K/DOQI guidelines protocol and adjusted every 3 months. Serum PTH, 25-vitamin D, 1,25-vitamin D, calcium, phosphorus, and albumin levels were drawn at initiation of therapy and repeated every 3 months. Results: The mean 25-vitamin D levels normalized in patients with stage 3 and 4 CKD, with values of 31.6 ± 2.2 ng/ml (78.8 ± 5.49 nmol/l) and 35.4 ± 1.9 ng/ml (88.4 ± 4.74 nmol/l), respectively (p < 0.0001). A median decrease in PTH concentrations of 13.1 and 2.0% was noted in patients with stage 3 and stage 4 CKD, respectively (p = 0.041, p = nonsignificant). Conclusions: Ergocalciferol therapy is a reasonable initial therapy for vitamin D deficiency associated with elevated PTH levels in stage 3 CKD. It does not appear to have equivalent benefits in stage 4 CKD.

Clinical Measures Identify Vitamin D Deficiency in Dialysis

“…Given the impairment in 1␣-hydroxylase activity that occurs with CKD, 25-hydroxyvitamin D levels have previously been thought to be a poor reflection of the traditional effects of vitamin D on mineral metabolism. Prior studies have identified a correlation between 25-hydroxyvitamin D and PTH principally in early CKD (37,38). Our finding of an association with PTH, echoing an earlier study (39), suggests that levels of 25-hydroxyvitamin D are also important in ESRD, even with respect to traditional actions on calcium homeostasis.…”

Hypovitaminosis D in Chronic Kidney Disease

“…In our study, we were unable to demonstrate any significant relationship between serum PTH and 25OHD levels on multivariate adjustment, leading us to conclude that suboptimal 25OHD may contribute only modestly to the hyperparathyroidism in CKD. This notion is further supported by three uncontrolled studies in which vitamin D supplementation led to statistically but not clinically significant decreases in serum PTH in patients with stage 3 CKD and no change in patients with stage 4 CKD (9,24,25). The magnitude of benefit of 25OHD supplementation on lowering serum PTH levels needs to be tested in randomized, controlled trials.…”

A Randomized Multicenter Trial of Paricalcitol versus Calcitriol for Secondary Hyperparathyroidism in Stages 3–4 CKD

“…Several studies have demonstrated that correction of calcidiol deficiency does not resolve the SHPT (17)(18)(19). Thus, most patients with CKD require VDRA therapy to control hyperparathyroidism.…”