Vitamin C supplementation lowers serum low-density lipoprotein cholesterol and triglycerides: a meta-analysis of 13 randomized controlled trials
Received 26 October 2007; received in revised form 11 January 2008; accepted 16 January 2008.
Abstract
Objective
Vitamin C has been shown to be an effective therapeutic for reducing total serum cholesterol, but epidemiologic studies have determined that low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol are actually better predictive measures of coronary heart disease risk. Therefore, the purpose of this study was to provide a comprehensive meta-analysis of randomized controlled trials to investigate the effect of vitamin C supplementation on LDL and HDL cholesterol as well as triglycerides in patients with hypercholesterolemia.
Methods
Thirteen randomized controlled trials published between 1970 and June 2007 were identified using Medline and a manual search. From the 13 trials, 14 separate group populations with hypercholesterolemia and who were supplemented with at least 500 mg/d of vitamin C for between 3 and 24 weeks were entered into the meta-analysis. This meta-analysis used a random-effects model; and the overall effect sizes were calculated for changes in LDL and HDL cholesterol, as well as triglyceride concentrations.
Results
The pooled estimate of effect for vitamin C supplementation on LDL and HDL cholesterol was −7.9 mg/dL (95% confidence interval [CI], −12.3 to −3.5; P = .000) and 1.1 mg/dL (95% CI, −0.2 to 2.3; not significant), respectively. The pooled estimate of effect for vitamin C supplementation on triglycerides was −20.1 mg/dL (95% CI, −33.3 to −6.8; P < .003).
Conclusion
Supplementation with at least 500 mg/d of vitamin C, for a minimum of 4 weeks, can result in a significant decrease in serum LDL cholesterol and triglyceride concentrations. However, there was a nonsignificant elevation of serum HDL cholesterol.
Assistant Professor, Department of Physiology and Biochemistry, National University of Health Sciences, Lombard, IL 60148
Department of Physiology and Biochemistry, National University of Health Sciences, 200 East Roosevelt Rd, Lombard, IL 60148, USA. Tel.: +1 630 889 6592.
ABSTRACT