title: Study protocol--metabolic syndrome, vitamin D and bone status in South Asian women living in Auckland, New Zealand: a randomised, placebo-controlled, double-blind vitamin D intervention.
abstract: BACKGROUND
  The identification of the vitamin D receptor in the endocrine pancreas suggests a role for vitamin D in insulin secretion. There is also some limited evidence that vitamin D influences insulin resistance, and thus the early stages of the development of type 2 diabetes.
  
  
  METHODS
  Eighty-four women of South Asian origin, living in Auckland, New Zealand, were randomised to receive either a supplement (4000IU 25(OH)D3 per day) or a placebo for 6 months. At baseline, all participants were vitamin D deficient (serum 25(OH)D3 <50 nmol/L), insulin resistant (HOMA-IR > 1.93) and/or hyperinsulinaemic, hyperglycemic or had clinical signs of dislipidaemia. Changes in HOMA-IR, lipids, parathyroid hormone, calcium and bone markers were monitored at 3 months and 6 months.
  
  
  CONCLUSIONS
  This randomised, controlled trial will be the first to investigate the effect of vitamin D supplementation on insulin resistance in non-diabetic subjects. It will subsequently contribute to the growing body of evidence about the role of vitamin D in metabolic syndrome. Registered clinical.
  
  
  BACKGROUND
  Registered clinical trial--Registration No. ACTRN12607000642482.
authors.affiliation: Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand. p.r.vonhurst@massey.ac.nz
authors.forename: Pamela R
authors.initials: PR
authors.lastname: von Hurst
authors.forename: Welma
authors.initials: W
authors.lastname: Stonehouse
authors.forename: Christophe
authors.initials: C
authors.lastname: Matthys
authors.forename: Cathryn
authors.initials: C
authors.lastname: Conlon
authors.forename: Marlena C
authors.initials: MC
authors.lastname: Kruger
authors.forename: Jane
authors.initials: J
authors.lastname: Coad
mesh_terms: D000328:Adult; D001208:Asia / Q000208:ethnology; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000008:administration & dosage* / Q000097:blood; D001842:Bone and Bones / Q000378:metabolism; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D024821:Metabolic Syndrome / Q000150:complications* / Q000188:drug therapy; D009520:New Zealand; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000188:drug therapy* / Q000208:ethnology
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D014807:Vitamin D