Leizhen Duan1, Ling Han1, Qin Liu1, Yili Zhao1, Lei Wang1, Yan Wang2
1Department of Medical Services, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, China
2Public Health and Preventive Medicine Teaching and Research Center, Henan University of Chinese Medicine, Zhengzhou, China
Tóm tắt
<b><i>Background:</i></b> The obesity pandemic has been paralleled by a high prevalence of vitamin D deficiency (VDD). There is growing epidemiological evidence linking low vitamin D status with obesity events. In addition, observational studies also show that obesity may increase the risk of VDD. However, there is insufficient knowledge to understand whether there is a causality between the two. Moreover, the impact of vitamin D supplementation on obesity indices has shown inconsistent outcomes. <b><i>Objective:</i></b> This meta-analysis aimed to assess whether vitamin D supplementation modified general and central obesity indices in apparently healthy populations. <b><i>Methods:</i></b> A systematic retrieval of relevant randomized controlled trials (RCTs) was undertaken using Pubmed, Embase, Web of Knowledge and Chinese National Knowledge Infrastructure databases. The pooled weighted mean difference (WMD) and 95% confidence intervals (CI) were used to assess the changes in body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and 25-hydroxyvitamin D (25[OH]D) from baseline. <b><i>Results:</i></b> Twenty RCTs involving 3,153 participants reporting either BMI, WC, WHR or 25(OH)D met the inclusion criteria. When compared with placebo, vitamin D supplementation had no significant decreases in BMI (WMD = –0.09 kg/m<sup>2</sup>, 95% CI –0.19 to 0.01, <i>p</i> = 0.08), WC (WMD = –0.71 cm, 95% CI –1.58 to 0.16, <i>p</i> = 0.112) or WHR (WMD = 0.00, 95% CI –0.01 to 0.01, <i>p</i> = 0.749). However, in the subgroups of females, Asia region studies and intervention duration ≥6 months, a beneficial and significant reduction in BMI and WC was noted (all <i>p</i> < 0.026). On the other hand, pooled results showed that there was a significant increase in serum 25(OH)D levels (WMD = 13.20 ng/mL, 95% CI 9.83–16.58, <i>p</i> < 0.001) after vitamin D intervention. No publication bias was found in our study. <b><i>Conclusions:</i></b> Overall, supplementation with vitamin D produced no significant effect on the BMI, WC or WHR of healthy adults.
