Effect of paricalcitol vs calcitriol on hemoglobin levels in chronic kidney disease patients: a randomized trial

PLoS One. 2015 Mar 17;10(3):e0118174. doi: 10.1371/journal.pone.0118174. eCollection 2015.


Background: Recent studies suggest that vitamin D deficiency represents an additional cofactor of renal anemia, with several mechanisms accounting for this relationship. In line with it, the administration of vitamin D or its analogues has been associated with an improvement of anemia. There are no data, however, about a direct effect of paricalcitol on hemoglobin (Hb) levels. Therefore, we conducted a study to determine whether paricalcitol, compared to calcitriol, improves anemia in patients with chronic kidney disease (CKD).

Methods: In this randomized trial 60 CKD patients stage 3b-5 and anemia (Hb levels: 10-12.5 g/dL) were assigned (1:1) to receive low doses of calcitriol (Group Calcitriol) or paricalcitol (Group Paricalcitol) for 6 months. All the patients had normal values of plasma calcium, phosphorus and PTH, a stable iron balance, and normal values of C-Reactive Protein. The primary endpoint was to evaluate the effects of the two treatments on Hb levels; the modifications in 24hr-proteinuria (UProt) were also evaluated.

Results: A significant Group x Time interaction effect was observed in the longitudinal analysis of Hb levels (F(1,172)=31.4, p<0.001). Subjects in Paricalcitol experienced a significant monthly increase of Hb levels equal to +0.16 g/dL [95% C.I. 0.10 to +0.22, p<0.001) while in Group Calcitriol, Hb decrease throughout the follow-up with an average monthly rate of -0.10 g/dL (95% C.I.: -0.17 to -0.04, p<0.001). In Group Paricalcitol, UProt was significantly reduced after 6 months [0.35 (0.1-1.2) vs 0.59 (0.2-1.6), p<0.01], whereas no significant difference emerged in Group Calcitriol. Plasma levels of calcium, phosphate, PTH and of inflammation markers remained in the normal range in both groups throughout the study.

Conclusions: Short-term exposure to paricalcitol results in an independent increase in Hb levels, which occurred with no modification of iron balance, inflammatory markers, and PTH plasma concentrations, and was associated with a decrease in UProt.

Trial registration: ClinicalTrials.gov NCT01768351.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • C-Reactive Protein / metabolism
  • Calcitriol / pharmacology*
  • Calcitriol / therapeutic use
  • Ergocalciferols / pharmacology*
  • Ergocalciferols / therapeutic use
  • Female
  • Follow-Up Studies
  • Hemoglobins / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Renal Insufficiency, Chronic / drug therapy*
  • Renal Insufficiency, Chronic / metabolism*
  • Treatment Outcome


  • Ergocalciferols
  • Hemoglobins
  • paricalcitol
  • C-Reactive Protein
  • Calcitriol

Associated data

  • ClinicalTrials.gov/NCT01768351

Grant support

The authors have no support or funding to report.