Abstract: SA-PO885

Effects of Vitamin D Supplementation on Markers of Bone and Mineral Metabolism in Pediatric Patients with Early and Late CKD

Session Information

  • Mineral Disease: CKD-Bone
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Mineral Disease

  • 1203 Mineral Disease: CKD-Bone

Authors

  • Haffner, Dieter, Hannover Medical School Children's Hospital, Hannover, Germany
  • Lerch, Christian, Hannover Medical School Children's Hospital, Hannover, Germany
  • Schaefer, Franz S., University Children’s Hospital Heidelberg, Heidelberg, Germany
  • Shroff, Rukshana, Great Ormond Street Hospital for Children, London, United Kingdom

Group or Team Name

  • ESPN CKD-MBD working group and 4C Study consortium
Background

Recent research findings suggest that vitamin D may have PTH independent effects on the regulation of bone and mineral metabolism. We investigated the effects of vitamin D supplementation on circulating fibroblast growth factor 23 (FGF23), Klotho, and sclerostin levels in two pediatric cohorts with early and late CKD.

Methods

Eighty vitamin D deficient children were selected: 40 with early CKD from the ERGO Study, a randomized placebo-controlled trial of ergocalciferol supplementation in children (mean eGFR 55 ml/min/1.73m2), and 40 with advanced CKD from the observational 4C Study (eGFR 24 ml/min/1.73m2, p<0.01). In each study 20 children received vitamin D supplementation, and 20 age and eGFR-matched children not on vitamin D served as controls. Z-scores (SDS) were calculated for serum levels of Klotho, FGF23, and sclerostin, at baseline and after a median period of 8 months.

Results

Untreated patients in the ERGO study had normal FGF23 (0.31 SDS) but decreased levels of klotho (-0.77 SDS) and sclerostin (-1.04 SDS), whereas untreated children in the 4C cohort had increased FGF23 (3.87 SDS) and sclerostin (0.76 SDS), but normal klotho (-0.27 SDS) levels. Vitamin D supplementation further increased FGF23 levels in 4C but not in ERGO patients. Serum klotho and sclerostin normalized during vitamin D supplementation in ERGO but remained unaffected in 4C patients. In the whole cohort significant differences between vitamin D treated patients and controls were noted for Klotho at eGFR 40-70 ml/min/1.73 m2 and for sclerostin at eGFR 60-70 ml/min/1.73 m2. 25-hydroxyvitamin D levels >75nMol/L was independently associated with the changes in Klotho and sclerostin levels.

Conclusion

Vitamin D supplementation normalizes Klotho and sclerostin levels in vitamin D deficient children with early CKD, but further increases FGF23 levels in vitamin D deficient children with advanced CKD.