Comment on "clinicians should be more prone to examine children with chronic kidney disease in terms of vitamin D deficiency".

To the Editor: We read the article “Vitamin D insufficiency and deficiency in children with chronic kidney disease” written by Kari et al with interest.1 The authors concluded that vitamin D insufficiency/deficiency was more frequent in children with chronic kidney disease (CKD) than in those with normal kidney function. Thank to the authors for their contribution of a study successfully designed. We believe that these findings will guide further studies about vitamin D levels and chronic renal failure.

A previous study including 400 adult healthy subjects in Saudi Arabia reported that 98 subjects (24.5%) had insufficiency (21–29 pg/mL) and 52 subjects (13%) had deficiency (<20 pg/mL) of 25OHD levels.2 Certainly the results in adult patients may not reflect the specifications of children, but some extrapolation of data can be made. The control group of the present study had similar results. In addition to the baseline levels in a healthy population, patients with CKD are expected to have lower levels of vitamin D due to the defective enzymatic transformation.3 Thus, the results of the study are expected. As in adults, CKD is a difficult challenge in terms of follow up, treatment and complications. This study deserves emphasis in terms of underlining the condition of vitamin D deficiency particularly in children with CKD. We think that treatment of calcium, phosphorus, parathyroid hormone and vitamin D levels are only part of the whole condition and clinicians should be more prone to examine patients in detail in terms of physical and laboratory findings in the follow up of CKD patients.