Effects of vitamin D supplementation on apolipoprotein A1 and B100 levels in adults: systematic review and meta-analysis of controlled clinical trials

Abstract

Abstract Background: Cardiovascular Disease (CVD) is a leading cause of death around the world. According to the studies, apolipoproteins A1 and B100 play crucial role in CVD development and progression. Also, findings have indicated the positive role of vitamin D on these factors. Thus, we conducted the present meta-analysis of randomized controlled trials (RCTs) to demonstrate the impact of vitamin D supplementation on apolipoproteins A1 and B100 levels in adults. Materials and Methods: PubMed and Scopus databases and Google Scholar were searched up to 21 December 2020. Relevant articles were screened, extracted, and assessed for quality based on the Cochrane collaboration’s risk of bias tool. Data analyses were conducted by random-effect model and expressed by standardized mean difference (SMD). The heterogeneity between studies was assessed by I-squared (I2) test. Subgroups and sensitivity Analyses were also conducted. Results: Seven RCTs were identified investigating the impact of vitamin D on Apo A1 levels and six on Apo B100 levels. The findings showed the insignificant effect of vitamin D supplementation on Apo A1 (SMD = 0.26 mg/dl; 95% CI, −0.10, 0.61; P = 0.155) and Apo B100 (SMD = -0.06 mg/dl; 95% CI, −0.24, 0.12; P = 0.530) in adults. There was a significant between-study heterogeneity in Apo A1 (I2 = 89.3%, p < 0.001) and Apo B100 (I2 = 57.1%, p = 0.030). However, significant increase in Apo A1 at daily dosage of vitamin D (SMD = 0.56 mg/dl; 95% CI, 0.02, 1.11; P = 0.044) and ≤12 weeks of supplementation duration (SMD = 0.71 mg/dl; 95% CI, 0.08, 1.34; P = 0.028) was observed, other subgroups analysis did not show any significant effects.Conclusion: Overall, daily vitamin D supplementation might have beneficial effects in increasing Apo A1 levels, however, future high quality trials considering these primary outcomes are required. Keywords: Vitamin D; Apolipoproteins; Meta-Analysis; Systematic Review; Randomized Controlled Trial