Vitamin D Insufficiency and Deficiency in Children with Early Chronic Kidney Disease
Received 28 July 2008; received in revised form 29 September 2008; accepted 1 December 2008. published online 23 February 2009.
Objective
To assess the prevalence of abnormal vitamin D status in children and adolescents with chronic kidney disease (CKD).
Study design
This was an outpatient cross-sectional, retrospective study of 258 patients, mean age 12.3 ± 5.2 years, with an average estimated glomerular filtration rate (eGFR) of 106 ± 51 mL/min/1.73 m2 (range, 0 to 220 mL/min/1.73 m2). Serum 25-hydroxy-vitamin D [25(OH)D], calcium, phosphorus, and parathyroid hormone levels, as well as selected anthropometric variables, were analyzed.
Results
Reduced 25(OH)D concentrations (< 30 ng/mL) were found in 60% of the patients. In 28%, the concentration was < 20 ng/mL, indicating vitamin D deficiency. Patients with more advanced CKD were more likely to have vitamin D deficiency compared with those with incipient CKD or normal GFR (42% vs 26%; P = .03) and displayed more prominent hyperparathyroidism. Suboptimal vitamin D status was similar in males and females, but was significantly more prevalent in older (P < .01), non-Caucasian (P < .01), and overweight (P = .02) patients. Patients with early-stage CKD (eGFR > 60 mL/min/1.73 m2) and with vitamin D deficiency were significantly shorter than their counterparts with 25(OH)D levels > 20 ng/mL (P = .02).
Conclusions
Vitamin D insufficiency and deficiency are very prevalent in pediatric patients across all stages of CKD, particularly in non-Caucasian and obese patients, and may contribute to growth deficits during the earliest stages of CKD.
Department of Pediatrics, Division of Pediatric Nephrology and Holtz Children's Hospital, Miller School of Medicine, University of Miami, Miami, FL
Reprint requests: Michael Freundlich, MD, Department of Pediatrics, Division of Pediatric Nephrology, Miller School of Medicine, University of Miami, PO Box 016960 (M-714),Miami,FL 33101
Limited portions of this study were presented as an abstract at the annual meeting of the American Society of Nephrology, San Francisco, CA, in October, 2007.
ABSTRACT