title: Cholecalciferol supplementation does not influence β-cell function and insulin action in obese adolescents: a prospective double-blind randomized trial.
abstract: BACKGROUND
  There is increasing interest in the extraskeletal effects of vitamin D, particularly in the obese state with regard to the development of insulin resistance and diabetes.
  
  
  OBJECTIVE
  The objective of the study was to determine the effect of 2 doses of cholecalciferol (vitamin D3) supplementation on insulin action (Si) and pancreatic β-cell function in obese adolescents.
  
  
  METHODS
  We performed a 12-wk double-blind, randomized comparison of the effect of vitamin D3 supplementation on Si and β-cell function in obese Caucasian adolescents (body mass index > 95(th) percentile). The subjects were randomly assigned to receive either 400 IU/d (n = 25) or 2000 IU/d (n = 26) of vitamin D3. Each subject underwent a 7-sample 75 g oral glucose tolerance test, with glucose, insulin, and C-peptide measurements, to calculate Si and β-cell function as assessed by the disposition index (DI), with use of the oral minimal model before and after supplementation. A total of 51 subjects aged 15.0 ± 1.9 y were enrolled. Included for analysis at follow-up were a total of 46 subjects (20 male and 26 female adolescents), 23 in each group.
  
  
  RESULTS
  Initial serum 25-hydroxyvitamin D [25(OH)D] was 24.0 ± 8.1 μg/L. There was no correlation between 25(OH)D concentrations and Si or DI. There was a modest but significant increase in 25(OH)D concentration in the 2000 IU/d group (3.1 ± 6.5 μg/L, P = 0.04) but not in the 400 IU/d group (P = 0.39). There was no change in Si or DI following vitamin D3 supplementation in either of the treatment groups (all P > 0.10).
  
  
  CONCLUSIONS
  The current study shows no effect from vitamin D3 supplementation, irrespective of its dose, on β-cell function or insulin action in obese nondiabetic adolescents with relatively good vitamin D status. Whether obese adolescents with vitamin D deficiency and impaired glucose metabolism would respond differently to vitamin D3 supplementation remains unclear and warrants further studies. This trial was registered at clinicaltrials.gov as NCT00858247.
authors: Divisions of Pediatric Endocrinology and.
authors: Asma
authors: A
authors: Javed
authors: Division of Endocrinology and Metabolism.
authors: Adrian
authors: A
authors: Vella
authors: Nemours Children's Clinic, Research Division, Jacksonville, FL; and.
authors: P Babu
authors: PB
authors: Balagopal
authors: General Pediatric and Adolescent Medicine, Department of Pediatric and Adolescent Medicine.
authors: Philip R
authors: PR
authors: Fischer
authors: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
authors: Amy L
authors: AL
authors: Weaver
authors: Information Engineering and.
authors: Francesca
authors: F
authors: Piccinini
authors: Department of Electronics and Informatics, University of Padua, Padua, Italy.
authors: Chiara
authors: C
authors: Dalla Man
authors: Department of Electronics and Informatics, University of Padua, Padua, Italy.
authors: Claudio
authors: C
authors: Cobelli
authors: Endocrine Research Unit, Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Department of Internal Medicine, and.
authors: Paula D
authors: PD
authors: Giesler
authors: Endocrine Research Unit, Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Department of Internal Medicine, and.
authors: Jeanette M
authors: JM
authors: Laugen
authors: Divisions of Pediatric Endocrinology and kumar.seema@mayo.edu.
authors: Seema
authors: S
authors: Kumar
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002648:Child; D002762:Cholecalciferol / Q000008:administration & dosage* / Q000097:blood; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D064368:Healthy Volunteers; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000097:blood*; D011446:Prospective Studies; D016896:Treatment Outcome; D014815:Vitamins / Q000008:administration & dosage
chemical_list: D001786:Blood Glucose; D007328:Insulin; D014815:Vitamins; D002762:Cholecalciferol
keywords: disposition index; insulin action; insulin secretion; obese adolescents; vitamin D supplementation
references: Am J Clin Nutr. 2000 Sep;72(3):690-3
references: 10966885
references: IEEE Trans Biomed Eng. 2002 May;49(5):419-29
references: 12002173
references: Vital Health Stat 11. 2002 May;(246):1-190
references: 12043359
references: Pediatrics. 1998 Mar;101(3 Pt 2):518-25
references: 12224658
references: Arch Pediatr Adolesc Med. 2003 Aug;157(8):821-7
references: 12912790
references: Arch Dis Child. 2003 Sep;88(9):748-52
references: 12937090
references: Diabetes. 2004 May;53(5):1201-7
references: 15111487
references: Am J Physiol Endocrinol Metab. 2004 Oct;287(4):E637-43
references: 15138152
references: N Engl J Med. 2004 Jun 3;350(23):2362-74
references: 15175438
references: Arch Pediatr Adolesc Med. 2004 Jun;158(6):531-7
references: 15184215
references: Diabetes. 1992 Mar;41(3):368-77
references: 1551497
references: Am J Physiol Endocrinol Metab. 2005 Dec;289(6):E954-9
references: 16014353
references: J Pediatr Adolesc Gynecol. 2005 Oct;18(5):305-11
references: 16202933
references: J Clin Endocrinol Metab. 2007 Jun;92(6):2017-29
references: 17389701
references: N Engl J Med. 2007 Jul 19;357(3):266-81
references: 17634462
references: J Pediatr Endocrinol Metab. 2007 Jul;20(7):817-23
references: 17849744
references: Metabolism. 2008 Feb;57(2):183-91
references: 18191047
references: Br J Nutr. 2008 May;99(5):1061-7
references: 18197989
references: Arch Pediatr Adolesc Med. 2008 Jun;162(6):513-9
references: 18524740
references: Diabetes Care. 2009 Jan;32(1):14-8
references: 18931099
references: Am J Clin Nutr. 2008 Dec;88(6):1519-27
references: 19064511
references: J Clin Endocrinol Metab. 2009 Sep;94(9):3200-6
references: 19549742
references: Pediatrics. 2009 Sep;124(3):e371-9
references: 19661053
references: Pediatrics. 2009 Sep;124(3):e362-70
references: 19661054
references: J Pediatr. 2010 Mar;156(3):444-9
references: 19926097
references: Int J Endocrinol. 2010;2010:351385
references: 20011094
references: J Nutr. 2010 May;140(5):987-91
references: 20237070
references: Am J Clin Nutr. 2010 Jul;92(1):69-76
references: 20484452
references: Diabetes Care. 2011 Mar;34(3):646-8
references: 21273498
references: Arch Dis Child. 2011 May;96(5):447-52
references: 21335626
references: J Adolesc Health. 2011 May;48(5):448-52
references: 21501802
references: J Clin Endocrinol Metab. 2012 Jan;97(1):279-85
references: 22072738
references: Diabetes Care. 2012 Mar;35(3):627-33
references: 22238280
references: Diabetes Care. 2012 May;35(5):1133-8
references: 22410810
references: Diabet Med. 2012 Aug;29(8):e142-50
references: 22486204
references: Diabetes Obes Metab. 2012 Sep;14(9):789-94
references: 22486948
references: Horm Res Paediatr. 2012;78(4):226-31
references: 23128469
references: Pediatrics. 2013 Jan;131(1):e152-61
references: 23266927
references: Diabetes Care. 2013 Jul;36(7):2048-53
references: 23340897
references: Am J Clin Nutr. 2013 Apr;97(4):774-81
references: 23407306
references: Diabetes. 2014 Apr;63(4):1203-13
references: 24651807
references: Atherosclerosis. 2014 Jul;235(1):130-9
references: 24835432
references: Horm Res Paediatr. 2014;82(2):107-12
references: 25034315
references: Am J Physiol. 1994 Sep;267(3 Pt 1):E356-60
references: 7943215