Vitamin D insufficiency is common in patients with chronic kidney disease (CKD) and may contribute to mineral bone disease. In a prospective interventional study, we estimated the prevalence of vitamin D insufficiency (serum 25-hydroxyvitamin D3 [25OHD] < 30 ng/ml), and examined the effect of high-dose (600,000 IU) cholecalciferol supplementation after 6 weeks on serum 25OHD and parathyroid hormone (PTH) levels in children with CKD stages 2-4.

Forty-two children (86% boys) with a mean age of 7.7 ± 3.8 (range 2--5) years were studied. Thirty-seven children (82.1%) had vitamin D insufficiency; 18 (42.8%) had 25OHD < 16 ng/ml. The median 25OHD increased significantly from 16.7 (95% CI 11.3, 19.8) to 46.2 (34.5, 44.6) ng/ml in patients with vitamin D insufficiency (P <0.001). The median PTH decreased significantly from 51.3 (95% CI 46.7, 71.5) to 37.1 (29.0, 54.6) pg/ml (P = 0.003).

Nineteen patients (47.5%) had >30% reduction in the PTH after supplementation. Serum calcium, phosphorus, and estimated GFR did not change significantly.

We conclude that vitamin D insufficiency is highly prevalent in children with CKD stages 2-4. High-dose cholecalciferol is safe and effective in correcting vitamin D insufficiency and results in a significant reduction in PTH levels in vitamin D-insufficient children.