Nutritional vitamin D therapy (NVD) does not reliably lower parathyroid hormone levels (PTH) in patients with nondialysis-dependent chronic kidney disease (NDD-CKD) and secondary hyperparathyroidism (SHPT), according to a poster presentation at the American Society of Nephrology’s Kidney 2020 Week Reimagined virtual conference.

In a meta-analysis of 14 randomized trials, 9 (involving 745 patients) compared cholecalciferol or ergocalciferol with placebo- or untreated patients and 5 compared these NVDs with other active treatment. At baseline, the mean parathyroid hormone (PTH) concentration was 144 pg/mL and mean 25-hydroxyvitamin D (25(OH)D) value was 19.62 ng/mL.

PTH declined 10.53 pg/mL from baseline to trial end and 49.74 pg/mL compared with placebo or no treatment among patients receiving cholecalciferol or ergocalciferol, Joel Gunnarsson, MEc, of Quality Research in Stockholm, Sweden, and colleagues reported. Additionally, calcium levels significantly increased 0.23 mg/dL with NVD, but no significant effects from NVD were found on phosphate and fibroblast growth factor 23 (FGF23).

Meanwhile, among recipients of cholecalciferol or ergocalciferol, 25(OH)D levels increased 20.62 ng/mL from baseline and 26.87 ng/mL compared with placebo or no treatment. Mean 25(OH)D rose higher than 30 ng/mL in 12 trials but higher than 50 ng/mL in only 5 trials. According to the investigators, evidence suggests that 25(OH)D needs to exceed 50 ng/mL to substantively reduce PTH and bone turnover markers.


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“Although treatment with NVDs can likely be used to raise 25(OH)D above 30 ng/mL, there is a limited potential of NVD treatment to increase 25(OH)D levels above 50 ng/mL, which might be necessary for clinically meaningful PTH reductions,” Gunnarsson’s team stated. “The potential of NVDs to actively reduce PTH in ND-CKD patients with SHPT is limited.”

Disclosure: This clinical trial was supported by Vifor Pharma. Please see the original reference for a full list of authors’ disclosures.

Reference

Gunnarsson J, Cianciolo G, Lauppe R, et al. Meta-analysis of the impacts of supplementation with nutritional vitamin D on mineral and bone markers in non-dialysis CKD. Presented at: Kidney Week 2020 Reimagined, October 19-25, 2020. Poster PO0342.