title: Status of vitamin D in children with sickle cell disease living in Madrid, Spain.
abstract: Patients with sickle cell disease have vitamin D deficiency and poor bone health which makes them prone to have an increased risk of fractures and osteoporosis in adulthood. We performed a prospective, cross-sectional study in children diagnosed with sickle cell disease living in Madrid, Spain. The purpose of this study was to evaluate the status of vitamin D of these children. Patients 0-16 years old were enrolled between 2008 and 2011. We studied demographics, calcium metabolism, and bone health, especially by measuring levels of 25-hydroxyvitamin D (25(OH)D), during different seasons of the year, and bone densitometry (beyond 4 years of age). Seventy-eight children were included in the study. Mean age was 4.8 ± 4.3 years, and mean serum 25(OH)D level was 21.50 ± 13.14 ng/ml, with no differences in 25(OH)D levels within different seasons. Fifty-six percent of children had levels of 25(OH) vitamin D of <20 ng/ml, whereas 79 and 18 % of them had levels of <30 and <11 ng/ml, respectively. Secondary hyperparathyroidism was observed in 25 % of children. Densitometry was performed in 33 children, and an abnormal z-score was seen in 15.2 % of them with no correlation with levels of 25(OH)D.
  
  
  CONCLUSIONS
  Vitamin D deficiency is highly prevalent in children with sickle cell disease, who are residing in Madrid, Spain, and it is detected at a young age. We propose that early intervention may increase the possibility of an adequate bone density later in life.
authors.affiliation: Division of Pediatric Hematology and Oncology, Department of Pediatrics Medicine, Hospital General Universitario Gregorio Marañón, Maiquez 9, 28007 Madrid, Spain. cgccolino@gmail.com
authors.forename: Carmen
authors.initials: C
authors.lastname: Garrido
authors.forename: Elena
authors.initials: E
authors.lastname: Cela
authors.forename: Cristina
authors.initials: C
authors.lastname: Beléndez
authors.forename: Cristina
authors.initials: C
authors.lastname: Mata
authors.forename: Jorge
authors.initials: J
authors.lastname: Huerta
mesh_terms: D000293:Adolescent; D000465:Algorithms; D000755:Anemia, Sickle Cell / Q000097:blood / Q000150:complications*; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D014807:Vitamin D; C104450:25-hydroxyvitamin D