Effects of Vitamin D Supplementation on Lipid Profile in Adults with the Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Background: Metabolic syndrome (MetS) increases the risk of cardiovascular disease, with atherogenic dyslipidemia being a major contributing factor. Methods: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to assess whether vitamin D supplementation (VDS) alleviates dyslipidemia in adults with MetS. Scientific databases (PUBMED, MEDLINE, CINAHL, EMBASE, Cochrane Library, ClinicalTrials.gov, International Clinical Trials Registry Platform) and the gray literature were searched for randomized controlled trials of VDS, reporting on blood lipids. A narrative review, meta-analyses, sensitivity analyses, and appraisal of the risk of bias and overall quality of evidence produced were conducted. Results: Seven studies were included, and four were meta-analyzed. The risk of bias was generally low, and the final quality of evidence was low or very low. VDS, whether in high or low dose, significantly increased endline vitamin D blood levels; did not affect total, low-density, high-density cholesterol levels, and novel lipid-related biomarkers; yet, significantly increased triglycerides (TG) levels compared with placebo (MD: 30.67 (95%CI: 4.89–56.45) mg/dL; p = 0.02 for low-dose VDS; and MD: 27.33 (95%CI: 2.06–52.59) mg/dL; p = 0.03 for high-dose VDS). Pertaining heterogeneity was high (I2 = 86%; and I2 = 51%, respectively), and some included studies had significantly higher baseline TG in the intervention arm. The sensitivity analyses revealed robust results. Conclusion: VDS seems not to affect blood lipids in adults with MetS.

Vitamin D Status and Its Correlation With Anthropometric and Biochemical Indicators of Cardiometabolic Risk in Serbian Underground Coal Miners in 2016

“…Triglycerides and HDL-cholesterol generally have an inverse association ( 102 , 103 ), which we confirmed in this study (Spearman's coefficient of correlation = −0.615, p < 0.001), and the linear regression analysis identified only triglycerides as significant predictors of VitD levels. Interestingly, and in line with this study findings, some studies show that VitD supplementation increased the levels of triglycerides ( 104 – 106 ), even though both unchanged ( 107 – 109 ) and decreased ( 110 ) levels were found in other studies. Therefore, we hypothesize that the observed positive relationship of VitD with serum triglycerides reflects the effect of positive association with lipolysis after an enduring physical work ( 89 ).…”

Mechanisms Involved in the Relationship between Vitamin D and Insulin Resistance: Impact on Clinical Practice

“…Thus, Farrokhian et al found no significant changes in lipid profile after vitamin D supplementation, although they reported changes in plasma malonaldehyde levels, which results from lipid peroxidation [147]. Similarly, AlAnouti et al reports inconsistent results on the relationship between vitamin D status and dyslipidemia in MS adults, pointing mainly to a lack of effect, despite improved vitamin D status [148]. However, the authors indicate that these results should be interpreted with caution given the limited number of included clinical trials RCTs, the small sample size, and the limited intervention period.…”

Vitamin D, respiratory infections, and chronic disease: Review of meta‐analyses and randomized clinical trials

“…One-year supplementation with vitamin D 3 at 4000 IU/day did not affect CVD, lipid profiles, or C-reactive protein levels in patients with type 2 diabetes, but did lower triglyceride (TG) levels [150]. Another trial reported that supplementation with vitamin D at 150,000 IU every 3 months failed to alter inflammatory markers and lipids in adults with metabolic syndrome [151]. A Cochrane review including 159 RCTs suggested that vitamin D supplementation may reduce all-cause mortality compared with placebo or no intervention, but had no significant effect on cardiovascular mortality [152] (Table 3).…”