Vahidreza Ostadmohammadi, Alireza Milajerdi, Majid Ghayour-Mobarhan, Gordon Ferns, Mohsen Taghizadeh, Bita Badehnoosh, Hamed Mirzaei and Zatollah Asemi*
Background: Insulin resistance, dyslipidemia and chronic inflammation are important risk factors for cardiovascular disease (CVD). Hence, vitamin D supplementation might be an appropriate approach to decrease the complications of CVD. This systematic review and meta-analysis aimed to determine the effects of vitamin D supplementation on glycemic control, lipid profiles, and C-reactive protein among patients with coronary artery disease.Methods: Two independent authors systematically searched online database including EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science were searched until 20th September 2018. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of included trials. The heterogeneity among the included studies was assessed using Cochran’s Q test and I-square (I2) statistic. Data were pooled using a random-effects model and weighted mean difference (WMD) was considered as the overall effect size. Results: A total of eight trials (305 participants in the intervention group and 325 in placebo group) were included in the current meta-analysis. Pooling effect sizes from studies revealed a significant reduction in fasting glucose (WMD): -15.67; 95% CI: -29.32, -2.03), insulin concentrations (WMD: -3.53; 95% CI: -4.59, -2.46) and homeostatic model assessment of insulin resistance (WMD: -1.07; 95% CI: -1.49, -0.66), and significant increase in the quantitative insulin-sensitivity check index (WMD: 0.02; 95% CI: 0.01, 0.03) following the administration of vitamin D. In addition, pooled analysis revealed a significant increase in serum HDL-cholesterol concentrations following vitamin D therapy (WMD: 3.08; 95% CI: 1.42, 4.73). Additionally, vitamin D supplementation significantly reduced C-reactive protein (CRP) levels (WMD: -0.75; 95% CI: -1.28, -0.23). Conclusions: This meta-analysis demonstrated the beneficial effects of vitamin D supplementation on improving glycemic control, HDL-cholesterol and CRP levels among patients with CVD, though it did not affect triglycerides, total- and LDL-cholesterol levels.
Vitamin D, insulin resistance, lipid profiles, cardiovascular disease, meta-analysis
Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kasha, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Metabolic Syndrome Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, , Brighton & Sussex Medical School, Division of Medical Education, Falmer, Brighton, Sussex BN1 9PH, Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Department of Gynecology and Obstetrics, School of Medicine, Alborz University of Medical Sciences, Karaj, Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan