EFFECT OF VITAMIN C SUPPLEMENTATION ON SERUM C-REACTIVE PROTEIN LEVEL: A META-ANALYSIS OF RANDOMIZED CONTROLLED TRIAL

Background and Aim: C-reactive protein is a biomarker of systematic inflammation, which play a pathogenic role in chronic disease. Antioxidants such as vitamin C may have an anti-inflammatory role. However, the results of clinical trials are inconsistent about the effect of vitamin C supplementation on CRP concentration. To determine the effect of vitamin C supplementation on serum level of CRP, this systematic review and meta-analysis of randomized controlled trials (RCTs) was performed. Methods: We searched Pub-Med and Scopus databases up to October 2017. Random effect model (Dersimonian-Liard) was applied to estimate mean difference (MD). Using Cochran’s Q and I2 tests, heterogeneity was evaluated. Subgroup analysis based on pre-specified criteria including age, duration, dosage, baseline CRP and healthy status were done to identify the potential sources of heterogeneity.Results: Among 1305 potentially relevant studies, ten studies were eligible for inclusion. Sample size in intervention group was 418 and in control group was 411. The meta-analysis indicated that vitamin C supplementation result in significant reduction in CRP concentration with MD of -0.95 mg/L (95% confidence interval [CI]: -1.56, -0.34; P = 0.002; I2 =35.3%). Conclusion: These beneficial effect is more in duration <8 weeks than ≥8, baseline CRP ≥3 mg/L than <3, and individuals with diseased status than healthy status. In conclusion, vitamin C supplementation could improve CRP level, particularly in individuals with diseased status and high baseline CRP.

کلیدواژه ها:

Supplementation ، vitamin C ، C - reactive protein ، inflammation ، meta-analysis