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. 

Conclusion: This study showed that decreased insulin resistance is expected by administrating vitamin D supplement in first-degree relatives of the patients with diabetes mellitus.

Trial Registration: The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the IRCT ID: 201105176430N1.

Funding: The authors received no financial support for the research or publication of this article.


Keywords: Vitamin D, Type 2 diabetes, Adiponectin, Insulin resistance, First degree relatives
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Current Issue

July-September 2019 (Volume 11, Issue 3)


Previous Issue

In the second issue of the journal Electronic Physician for 2019, we have several papers including four Randomized Controlled Trials, a model development study, a case report, an editorial, a letter to editor (LTE), and several original research including two studies with qualitative approach. Authors of this issue are from nine countries: Iran, The Netherlands, Sweden, Italy, India, Thailand, Saudi Arabia, United Arab Emirates (UAE), and Jordan. Read more...


The 6th World Conference on Research Integrity (WCRI) is to be held on June 2-5, 2019 in Hong Kong.

The WCRI is the largest and most significant international conference on research integrity. Since the first conference in Lisbon in 2007, it has given researchers, teachers, funding agencies, government officials, journal editors, senior administrators, and research students opportunities to share experiences and to discuss and promote integrity in research. Read more:


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Deadline for submission: 7 March 2019, 16:00 (GMT)

TDR provides fellowships for early- to mid-career researchers and clinical trial staff (e.g. clinicians, pharmacists, medical statisticians, data managers, other health researchers) in low- and middle-income countries (LMICs) to learn how to conduct clinical trials. Read more:

Meta-Analysis Workshops in New York, USA, and London, UK, in April and May 2019

Don't miss this exceptional opportunity to learn how to perform and report a Meta-analysis correctly. Two Meta-analysis workshops are organized in April and May 2019 by Dr. Michael Borenstein in New York, USA (April 08-10, 2019) and London, UK (May 27-29).

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Dr. Michael Borenstein, one of the authors of Introduction to Meta-Analysis, is widely recognized for his ability to make statistical concepts accessible to researchers as well as to statisticians. He has lectured widely on meta-analysis, including at the NIH, CDC, and FDA. Read more: