The association between vitamin C dietary intake and its serum levels with anthropometric indices: A systematic review and meta-analysis

Abstract

Background: studies showed inflammatory background of overweight and obesity. Prevalence of weight disorders has dramatically increased over the past few decades. Vitamin C is an antioxidant and may be associated with weight disorders. This study aims to systematically review the relationship between dietary and serum vitamin C levels with anthropometric indices. Methods: A systematic search was conducted in Medline database (PubMed), Scopus, Embase, Web of Science, Cochrane library and Google Scholar up to the end of August 2021. All observational studies that assessed the relationship between dietary or circulating vitamin C levels and body mass index (BMI) and waist circumference (WC) on adults were included. The quality of included studies was assessed using the National Institute of Health quality assessment tool.Results: Among 11,689 studies, 47 and 37 articles were included in the systematic review and meta-analysis, respectively. There was an inverse significant correlation between WC and serum vitamin C levels (r =-0.28, 95 CI: -0.35,-0.21, I2 = 14.2) and between BMI and serum vitamin C levels (r =-0.17, 95 CI:-0.25,-0.09, I2 = 72.8). Higher vitamin C consumption was significantly associated with lower BMI. There were no significant differences in serum vitamin C levels between normal-weight and overweight subjects, but serum vitamin C levels were significantly higher in obese subjects in comparison with normal-weight subjects.Conclusion: Results showed that both dietary and serum vitamin C levels were inversely associated with BMI and WC. More well-designed clinical trials are needed to assess the effect of vitamin C supplementation in prevention and treatment of obesity.