To the Editor,

After having read the interesting article by Dr Hervás Sánchez et al on the effectiveness of treatment with paricalcitol in patients with pre-dialysis chronic kidney disease,1 we would like to take the time to make a few comments.

This study correctly describes the results obtained in controlling hyperparathyroidism and meeting the calcium, phosphorus and parathyroid hormone (PTH) target values recommended by the S.E.N. and KDOQI guidelines.2 The study was undertaken in normal clinical practice conditions with a retrospective analysis of 92 patients in stage 3 or 4 CKD, and the conclusion was that treatment with paricalcitol was effective for meeting the target values.

However, the data analysis section includes a piece of information that the authors did not comment at all. Levels of 25-OH vitamin D in their population were quite deficient, as occurs frequently in such cohorts.3 Mean recorded levels were 16.2±8ng/ml and 75% had levels below 21ng/ml.

We would like to issue a reminder that both the KDOQI and S.E.N. 2011 guidelines recommend starting native vitamin D treatment if 25-OH D levels are below 30ng/ml, and they only indicate treatment with active vitamin D if PTH values exceed the established target once 25-OH D levels have been normalised.

This aspect is relevant for two reasons:

1. From a clinical viewpoint, it is important to reach the right plasma levels of 25-OH vitamin D. By doing so, we will achieve better control over hyperparathyroidism, in addition to an array of other effects that we will not list in this brief discussion. This is also true in stage 5 chronic kidney disease,4 but it is especially relevant in earlier stages, such as those in the study in question. This does not mean that paricalcitol cannot be indicated as treatment for bone and mineral metabolism disorders, but it should not be used as a first-line treatment.

2. The economic impact of this decision is considerable. The estimate cost of treatment with native vitamin D is 20 to 30 Euros per patient per year, while treatment with paricalcitol may be more than 1700 Euros yearly. And in the range of different vitamin D receptor activators, some options are much more economical and have also been shown to be equally effective.3 This reflection is especially relevant now that the sustainability of our health system is a matter for concern, in fact, many editorial comments have been published on the subject, both in Spain and internationally.5

Without a doubt, the most important consideration is benefit to the patient, and to achieve this, we should follow the recommendations in the guidelines.

Conflicts of interest

The authors affirm that they have no conflicts of interest related to the content of this article.