title: Effect of large doses of parenteral vitamin D on glycaemic control and calcium/phosphate metabolism in patients with stable type 2 diabetes mellitus: a randomised, placebo-controlled, prospective pilot study.
abstract: OBJECTIVE
  Vitamin D (D₃) status is reported to correlate negatively with insulin production and insulin sensitivity in patients with type 2 diabetes mellitus (T2DM). However, few placebo-controlled intervention data are available. We aimed to assess the effect of large doses of parenteral D3 on glycosylated haemoglobin (HbA(₁c)) and estimates of insulin action (homeostasis model assessment insulin resistance: HOMA-IR) in patients with stable T2DM.
  
  
  METHODS
  We performed a prospective, randomised, double-blind, placebo-controlled pilot study at a single university care setting in Switzerland. Fifty-five patients of both genders with T2DM of more than 10 years were enrolled and randomised to either 300,000 IU D₃ or placebo, intramuscularly. The primary endpoint was the intergroup difference in HbA(₁c) levels. Secondary endpoints were: changes in insulin sensitivity, albuminuria, calcium/phosphate metabolism, activity of the renin-aldosterone axis and changes in 24-hour ambulatory blood pressure values.
  
  
  RESULTS
  After 6 months of D₃ supply, there was a significant intergroup difference in the change in HbA(₁c) levels (relative change [mean ± standard deviation] +2.9% ± 1.5% in the D₃ group vs +6.9% ± 2.1% the in placebo group, p = 0.041) as HOMA-IR decreased by 12.8% ± 5.6% in the D₃ group and increased by 10% ± 5.4% in the placebo group (intergroup difference, p = 0.032). Twenty-four-hour urinary albumin excretion decreased in the D₃ group from 200 ± 41 to 126 ± 39, p = 0.021). There was no significant intergroup difference for the other secondary endpoints.
  
  
  CONCLUSIONS
  D₃ improved insulin sensitivity (based on HOMA-IR) and affected the course of HbA(₁c) positively compared with placebo in patients with T2DM.
authors.affiliation: Department of Medicine, Kantonsspital Bruderholz, University of Basel, Switzerland.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Jehle
authors.forename: Alessia
authors.initials: A
authors.lastname: Lardi
authors.forename: Barbara
authors.initials: B
authors.lastname: Felix
authors.forename: Henry N
authors.initials: HN
authors.lastname: Hulter
authors.forename: Christoph
authors.initials: C
authors.lastname: Stettler
authors.forename: Reto
authors.initials: R
authors.lastname: Krapf
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000652:urine; D001794:Blood Pressure / Q000187:drug effects; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood / Q000652:urine; D002762:Cholecalciferol / Q000008:administration & dosage*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism*; D004311:Double-Blind Method; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood / Q000652:urine; D010865:Pilot Projects; D011446:Prospective Studies; D014815:Vitamins / Q000008:administration & dosage*
chemical_list: D002117:Calcitriol; D002118:Calcium; D002762:Cholecalciferol; D006442:Glycated Hemoglobin; D007328:Insulin; D010281:Parathyroid Hormone; D010710:Phosphates; D014815:Vitamins