Calcitriol treatment in metabolic bone disease of prematurity with elevated parathyroid hormone: A preliminary study

• Calcitriol was associated with improvement in several MBD-related metabolic parameters
• PTH and TRP may be useful in evaluating MBD in neonates with intestinal compromise
• Markers of MBD were not different in early MBD vs MBD associated with fracture

ObjectiveTo describe the association of calcitriol treatment with the change in parathyroid hormone (PTH) and biochemical markers of bone disease in infants with metabolic bone disease of prematurity (MBD) and secondary hyperparathyroidism.Study designThis retrospective chart review examined serum intact PTH, serum calcium (Ca), serum phosphorus (P), serum alkaline phosphatase (APA), urine calcium/creatinine (UCa/Cr), and tubular reabsorption of phosphate (TRP) in 32 infants prior to and following calcitriol treatment for MBD with PTH >100 pg/ml. 25-hydroxyvitamin D concentrations were recorded.ResultsFollowing calcitriol treatment, PTH decreased from median (min/max) 220 (115/593) to 25 (3/259) pg/ml, p < 0.001; Ca increased from 9.9 (8.9/10.7) to 10.3 (9.7/11.3) mg/dl, p < 0.001; P increased from 4.3 (2.7/6.4) to 5.4 (2.9/7.4) mg/dl, p = 0.001; and TRP increased from 81 (59/98) to 91.5 (78/98) %, p = 0.03. APA did not differ pre-treatment: 616 (209/1193) vs. post-treatment 485 (196/1229) U/L, p = 0.12. Vitamin D deficiency was not present. Hypercalcemia with hypercalciuria occurred in 3/32 subjects, all normalized after dose reduction.ConclusionImprovements in MBD markers and lack of serious adverse effects suggest calcitriol may be a treatment option in infants with MBD and secondary hyperparathyroidism.