title: Effects of vitamin D on serum lipid profile in patients with type 2 diabetes: A meta-analysis of randomized controlled trials.
abstract: The effect of vitamin D on lipid profile in type 2 diabetic patients is controversial. This meta-analysis aimed to assess the effect of vitamin D on serum total cholesterol (TC), triglycerides (TG), low-density lipoproteins (LDL), and high-density lipoproteins (HDL) of these patients to elucidate the subject.
  
  
  
  Seven databases were searched and randomized controlled trials (RCTs) assessed the effect of vitamin D on lipid profile published until November 2015 were identified. Un-standardized mean difference and its corresponding 95% confidence interval (CI) was calculated from the effect sizes by using random effects model.
  
  
  
  We found 2220 articles in our systematic search, after exclusion of un-related studies we enrolled 17 studies comparing intervention group (received vitamin D) with control group (received placebo) in the meta-analysis. Vitamin D significantly reduced serum TC (-3.74 mg/dl, 95% CI: -7.13 to -0.34, P = 0.031), but serum TG did not show significant reduction (-4.90 mg/dl, 95% CI: -15.11-5.31, P = 0.347). Results confirmed the significant lowering effect of vitamin D on LDL in patients with T2D (-2.55 mg/dl, 95% CI: -4.83 to -0.26, P = 0.029), but change in serum HDL was negligible (-0.72 mg/dl, 95% CI: -1.27 to -0.17, P = 0.010). Subgroup analyses showed that the baseline serum 25-hydroxy vitamin D of patients, vitamin D dosage, intervention duration, and the method of vitamin D application influence the effect of vitamin D on lipid markers.
  
  
  
  This study demonstrated that vitamin D improved serum levels of TC, TG, and LDL in patients with T2D but changes of serum HDL was not satisfactory.
authors.affiliation: Department of Biochemistry and Nutrition, Faculty of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran; Medical Plants Research Center, Shahrekord University of Medical Sciences, Sharhekord, Iran. Electronic address: tinajafari15@yahoo.com.
authors.forename: Tina
authors.initials: T
authors.lastname: Jafari
authors.affiliation: Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord 34141, Iran.
authors.forename: Aziz A
authors.initials: AA
authors.lastname: Fallah
authors.affiliation: Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
authors.forename: Afshin
authors.initials: A
authors.lastname: Barani
mesh_terms: D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D019587:Dietary Supplements; D005527:Food, Fortified; D006801:Humans; D008055:Lipids / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D016032:Randomized Controlled Trials as Topic; D014280:Triglycerides / Q000097:blood; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D008055:Lipids; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; D014807:Vitamin D; D002784:Cholesterol; C104450:25-hydroxyvitamin D
keywords: Meta-analysis; Serum lipid profile; Type 2 diabetes; Vitamin D