IRCT2016062710826N19.

Background & aims: It is proposed that vitamin D supplementation might influence serum adipokines level; however, the recent meta-analyses have led to inconsistent results while they had methodological limitations. Therefore, this study aimed to examine the effects of vitamin D supplementation on serum adipokines through a systematic review and a meta-analysis of randomized placebo-controlled trials (RCTs) using a more comprehensive search strategy. Methods: PubMed, Google Scholar, and Scopus were searched to identify related articles published up to November 2017. Mean±standard deviation (SD) of changes in serum adiponectin and leptin were extracted, and the effect sizes were pooled using a random-effects model. Studies with Controlled clinical trials design were eligible. Two reviewers extracted mean values and SDs of the baseline, final and net change values of leptin and adiponectin in the intervention and control groups. Results: The pooled results indicated that vitamin D supplementation affects neither circulating leptin (Hedges’ g = 0.042, 95% CI: -0.294 to 0.378, p = 0. 0.807, n=15) nor adiponectin (Hedges’ g = -0.034, 95% CI: -0.243 to 0.174, p = 0.748, n=18) levels.  Subgroup analysis showed that vitamin D supplementation might significantly decrease serum leptin level in patients with end stage renal disease (Hedges’ g = -0.634, 95 % CI: -1.221 to -0.047, p = 0.034). Conclusions: Although the current evidence does not support the significant effect of vitamin D supplementation on adiponectin and leptin levels, further research is required to reach more definitive conclusions.

Background and Objectives: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive age women. In the present study, the effect of weight loss diet and vitamin D supplementation was investigated on total testosterone, anthropometric indices, and body composition in patients PCOS. Methods:In this controlled clinical trial, 60 PCOS women with vitamin D deficiency, were randomly received vitamin D3 supplementation orally at the dose of 50000IU/week along with weight-loss intervention or one placebo/week along with weight-loss diet for 12 weeks. At the beginning and the end of the study, indices, such as anthropometric, body composition, serum level of 25hydroxyvitamin D3, and total testosterone, were measured using parametric and non-parametric tests.Results: After a 12-week intervention, the median of serum 25hydroxyvitamin D3 significantly increased from 18.5 to 42.69ng/ml in vitamin D group compared to the placebo group (p<0.001). Moreover, the mean of weight, body mass index (BMI), Waist circumference, hip circumference, waist to hip ratio, and fat mass significantly decreased in both groups, but was not different between the two groups. The mean of total testosterone decreased from 0.7 to 0.5ng/ml in vitamin D group, which was not statistically significant. Conclusion:According to the results of this study, vitamin D supplementation in combination with low-calorie diet had no effect on total testosterone.