title: The effects of vitamin D supplementation on adiponectin level and insulin resistance in first-degree relatives of subjects with type 2 diabetes: a randomized double-blinded controlled trial.
abstract: BACKGROUND
  Despite the certain role of both vitamin D and adiponectin in the regulation of insulin sensitivity, the interaction between these two agents has remained uncertain.
  
  
  OBJECTIVE
  The present study aimed to determine whether vitamin D is able to change plasma adiponectin and affect glucose homeostasis and insulin sensitivity in first-degree relatives of subjects with type 2 diabetes.
  
  
  METHODS
  This randomized clinical trial was conducted at Clinic of Shahid Sadoughi Hospital in Yazd, Iran, from January 25, 2012 to December 25, 2014. In this randomized, double-blinded controlled trial, 64 first-degree relatives of type 2 diabetic patients were assigned randomly to receive either vitamin D supplement (50000 IU vitamin D tablet weekly) plus lifestyle change as the intervention group (n = 32) or placebo plus lifestyle change as the control group (n = 32) for twelve weeks (three months).
  
  
  RESULTS
  Fifty-three patients (28 in the intervention group and 25 in the control group) completed the study. Serum levels of vitamin D increased while insulin level and consequently insulin resistance (calculated by HOMA formula) significantly decreased in the case group (p-value <0.001 for all variables). Although the values of these three biomarkers showed a slight increase in control group, the changes were not statistically significant. The levels of the changes in other markers including adiponectin, Fasting Blood Sugar (FBS), triglyceride, and total cholesterol remained insignificant in both study groups after completing interventions compared with before interventions.
  
  
  CONCLUSIONS
  This study showed that decreased insulin resistance is expected by administrating vitamin D supplement in first-degree relatives of the patients with diabetes mellitus.
  
  
  BACKGROUND
  The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the IRCT ID: 201105176430N1.
  
  
  BACKGROUND
  The authors received no financial support for the research or publication of this article.
authors: MD, Endocrinologist, Assistant Professor, Department of Internal Medicine, Faculty of Medicine, Shahid Sadoughi University of medical sciences, Yazd, Iran.
authors: Seyed Mohammad
authors: SM
authors: Mohammadi
authors: MD, Internal Medicine Resident, Department of Internal Medicine, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Seyed Ahmad
authors: SA
authors: Eghbali
authors: MD, Endocrinologist, Associate Professor, Department of Internal Medicine, Faculty of Medicine, Shahid Sadoughi University of medical sciences, Yazd, Iran.
authors: Sedighah
authors: S
authors: Soheilikhah
authors: Researcher, Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Saeedeh Jam
authors: SJ
authors: Ashkezari
authors: MD, Endocrinologist, Assistant Professor, Department of Internal Medicine, Faculty of Medicine, Shahid Sadoughi University of medical sciences, Yazd, Iran.
authors: Maryam
authors: M
authors: Salami
authors: MD, Endocrinologist, Professor, Department of Internal Medicine, Faculty of Medicine, Shahid Sadoughi University of medical sciences, Yazd, Iran.
authors: Mohammad
authors: M
authors: Afkhami-Ardekani
authors: Medical Student, Faculty of Medicine, Tehran University of Medical Sciences. Tehran, Iran.
authors: Arezoo
authors: A
authors: Afkhami-Ardekani
keywords: Adiponectin; First degree relatives; Insulin resistance; Type 2 diabetes; Vitamin D