title: Daily consumption of vitamin D- or vitamin D + calcium-fortified yogurt drink improved glycemic control in patients with type 2 diabetes: a randomized clinical trial.
abstract: BACKGROUND
  Low serum concentrations of 25-hydroxyvitamin D [25(OH)D] have been associated with impaired glucose tolerance and diabetes.
  
  
  OBJECTIVE
  This study aimed to compare the effects of daily intake of vitamin D- or vitamin D(3) + calcium-fortified yogurt drink on glycemic status in subjects with type 2 diabetes (T2D).
  
  
  METHODS
  Ninety diabetic subjects were randomly allocated to 3 groups to consume plain yogurt drink (PY; containing no vitamin D and 150 mg Ca/250 mL), vitamin D-fortified yogurt drink (DY; containing 500 IU vitamin D(3) and 150 mg Ca/250 mL), or vitamin D + calcium-fortified yogurt drink (DCY; containing 500 IU vitamin D(3) and 250 mg Ca/250 mL) twice per day for 12 wk. Fasting serum glucose (FSG), glycated hemoglobin (Hb A(1c)), homeostasis model assessment of insulin resistance (HOMA-IR), serum lipid profile, and percentage fat mass (FM) were assessed before (baseline) and after the intervention.
  
  
  RESULTS
  In both the DY and DCY groups, mean serum 25(OH)D(3) improved (+32.8 ± 28.4 and +28.8 ± 16.1 nmol/L, respectively; P < 0.001 for both), but FSG [-12.9 ± 33.7 mg/dL (P = 0.015) and -9.6 ± 46.9 mg/dL (P = 0.035)], Hb A(1c) [-0.4 ± 1.2% (P < 0.001) and -0.4 ± 1.9% (P < 0.001)], HOMA-IR [-0.6 ± 1.4 (P = 0.001) and -0.6 ± 3.2 (P < 0.001)], waist circumference (-3.6 ± 2.7 and -2.9 ± 3.3; P < 0.001 for both), and body mass index [in kg/m(2); -0.9 ± 0.6 (P < 0.001) and -0.4 ± 0.7 (P = 0.005)] decreased significantly more than in the PY group. An inverse correlation was observed between changes in serum 25(OH)D(3) and FSG (r = -0.208, P = 0.049), FM (r = -0.219, P = 0.038), and HOMA-IR (r = -0.219, P = 0.005).
  
  
  CONCLUSIONS
  Daily intake of a vitamin D-fortified yogurt drink, either with or without added calcium, improved glycemic status in T2D patients. This trial was registered at clinicaltrials.gov as NCT01229891.
authors.affiliation: Laboratory of Nutrition Research, National Research Institute and Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Bahareh
authors.initials: B
authors.lastname: Nikooyeh
authors.forename: Tirang R
authors.initials: TR
authors.lastname: Neyestani
authors.forename: Maryamosadat
authors.initials: M
authors.lastname: Farvid
authors.forename: Hamid
authors.initials: H
authors.lastname: Alavi-Majd
authors.forename: Anahita
authors.initials: A
authors.lastname: Houshiarrad
authors.forename: Ali
authors.initials: A
authors.lastname: Kalayi
authors.forename: Nastaran
authors.initials: N
authors.lastname: Shariatzadeh
authors.forename: A'azam
authors.initials: A
authors.lastname: Gharavi
authors.forename: Soudabeh
authors.initials: S
authors.lastname: Heravifard
authors.forename: Nima
authors.initials: N
authors.lastname: Tayebinejad
authors.forename: Shabnam
authors.initials: S
authors.lastname: Salekzamani
authors.forename: Malihe
authors.initials: M
authors.lastname: Zahedirad
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001823:Body Composition; D015992:Body Mass Index; D002118:Calcium / Q000494:pharmacology / Q000627:therapeutic use*; D002762:Cholecalciferol / Q000494:pharmacology / Q000627:therapeutic use*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D005215:Fasting; D005260:Female; D005527:Food, Fortified; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D014807:Vitamin D / Q000097:blood; D014815:Vitamins / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D055105:Waist Circumference; D015014:Yogurt
chemical_list: D001786:Blood Glucose; D002118:Calcium; D002762:Cholecalciferol; D006442:Glycated Hemoglobin; D014807:Vitamin D; D014815:Vitamins