title: Daily intake of vitamin D- or calcium-vitamin D-fortified Persian yogurt drink (doogh) attenuates diabetes-induced oxidative stress: evidence for antioxidative properties of vitamin D.
abstract: BACKGROUND
  Both poor vitamin D status and oxidative stress (OS) have been independently associated with late diabetic complications, including cardiovascular disease (CVD). The present study aimed to examine the effect of daily intake of vitamin D alone or in combination with calcium as a fortified Persian yogurt drink (doogh) on OS over 12 weeks.
  
  
  METHODS
  Ninety patients with type 2 diabetes aged 30-50 years from both sexes were randomly allocated to one of the three groups to receive two 250-mL bottles of doogh a day, which was either plain (PD; containing 150 mg per 250 mL of calcium and no detectable vitamin D), vitamin D-fortified (DD; containing 150 mg of calcium + 500 IU vitamin D per 250 mL) or calcium-vitamin D-fortified (CDD; 250 mg od calcium + 500 IU vitamin D per 250 mL).
  
  
  RESULTS
  Although mean (SD) serum concentrations of protein carbonyl significantly decreased in both DD and CDD groups [-2.07 (4.39) nm, P = 0.015 and -4.4 (7.64) nm, P = 0.003, respectively], the change in PD group was not significant [-0.54 (6.96) nm, P = 0.674]. A similar pattern was observed for cardiac myeloperoxidase [PD: -19.4 (75.9) μg L(-1) , P = 0.173; DD: -21.8 (54.2) μg L(-1) , P = 0.035, CDD: -48.5 (76.9) μg L(-1) , P = 0.002]. Superoxide dismutase increased significantly only in DD and CDD [56.9 (74.0) U L(-1) , P < 0.001 and 51.6 (119.9) U L(-1) , P = 0.025, respectively]. Changes of serum advanced glycation end-products showed a significant between-group difference among PD, DD and CDD [239.4 (388.4) U L(-1) , -58.1 (147.6) U L(-1) and -143.7 (475.9) U L(-1)  × 10(3) , respectively, P = 0.003], which remained significant after controlling for changes of fasting serum glucose (P = 0.013) and glycated haemoglobin (P = 0.015).
  
  
  CONCLUSIONS
  The findings of the present study demonstrated an OS attenuating effect of vitamin D. However, extra calcium did not convey additional benefit.
authors.affiliation: Laboratory of Nutrition Research, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: B
authors.initials: B
authors.lastname: Nikooyeh
authors.forename: T R
authors.initials: TR
authors.lastname: Neyestani
authors.forename: N
authors.initials: N
authors.lastname: Tayebinejad
authors.forename: H
authors.initials: H
authors.lastname: Alavi-Majd
authors.forename: N
authors.initials: N
authors.lastname: Shariatzadeh
authors.forename: A
authors.initials: A
authors.lastname: Kalayi
authors.forename: M
authors.initials: M
authors.lastname: Zahedirad
authors.forename: S
authors.initials: S
authors.lastname: Heravifard
authors.forename: S
authors.initials: S
authors.lastname: Salekzamani
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D004311:Double-Blind Method; D005260:Female; D005527:Food, Fortified; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D014807:Vitamin D / Q000008:administration & dosage* / Q000097:blood; D015014:Yogurt
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D002136:Calcium, Dietary; D014807:Vitamin D
keywords: calcium; oxidative stress; type 2 diabetes; vitamin D