title: Seasonal variations in vitamin D in relation to growth in short prepubertal children before and during first year growth hormone treatment.
abstract: OBJECTIVE
  This study investigated the relationship between seasonal variations in 25-hydroxyvitamin D (25(OH)D) levels and growth in prepubertal children during both the pretreatment year and the first year of GH treatment.
  
  
  METHODS
  The study included 249 short prepubertal children with a broad range of GH secretion, GH(max) during a 24 h profile median 23; range 1-127 mU/L, 191 boys (mean age ± SD, 8.6 ± 2.6 years), 58 girls (7.5 ± 1.9 years) receiving GH treatment (mean 43 µg/kg/day; range 17-99 µg/kg/day). Serum 25(OH)D was measured using an automated IDS-iSYS immunoassay.
  
  
  RESULTS
  25(OH)D levels showed seasonal variation, and decreased significantly during GH treatment. 25(OH)D levels at start and first year reduction in 25(OH)D, correlated (-) with the first year growth response during treatment. The degree of GH secretion capacity within our study population of mainly non-GH deficient children and 25(OH)D sufficient (67 ± 29 nmol/L) had no influence on 25(OH)D levels. Growth during GH treatment were independent of seasonal variations in 25(OH)D. Multiple regression analysis showed that 25(OH)D levels at treatment start, together with auxological data and IGF-binding protein-(3)SDS, explained 61 % of the variation in first year gain in heightSDS.
  
  
  CONCLUSIONS
  25(OH)D levels were associated with first year growth response to GH and may be a useful contribution to future growth prediction models.
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, SE-405 30, Göteborg, Sweden. bjorn.andersson@medic.gu.se.
authors.forename: B
authors.initials: B
authors.lastname: Andersson
authors.affiliation: Göteborg Pediatric Growth Research Center, Department of Pediatrics, Institute of Clinical Sciences, The Sahlgrenska Academy at the University of Gothenburg, Göteborg, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Swolin-Eide
authors.affiliation: Institution of Clinical Sciences/Pediatrics, Umeå University, Umeå, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Kriström
authors.affiliation: Göteborg Pediatric Growth Research Center, Department of Pediatrics, Institute of Clinical Sciences, The Sahlgrenska Academy at the University of Gothenburg, Göteborg, Sweden.|Angered Hospital, Göteborg, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Gelander
authors.affiliation: Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Magnusson
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, SE-405 30, Göteborg, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Albertsson-Wikland
mesh_terms: D002648:Child; D005260:Female; D006130:Growth Disorders / Q000097:blood* / Q000188:drug therapy*; D013006:Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D012621:Seasons; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; D013006:Growth Hormone; C104450:25-hydroxyvitamin D
keywords: 25-Hydroxyvitamin D; Growth hormone; Growth response