The cross-sectional relationship between vitamin C and high-sensitivity C-reactive protein levels: insights from NHANES database

Ning Ding; Zhao Zeng; Ju Luo; Keng Li

doi:10.3389/fnut.2023.1290749

The cross-sectional relationship between vitamin C and high-sensitivity C-reactive protein levels: insights from NHANES database

Front Nutr. 2023 Nov 10:10:1290749. doi: 10.3389/fnut.2023.1290749. eCollection 2023.

Authors

Ning Ding^#¹, Zhao Zeng^#¹, Ju Luo^#², Keng Li¹

Affiliations

¹ Department of Emergency Medicine, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China.
² Department of Geriatrics, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China.

^# Contributed equally.

Abstract

Background: Ascorbic acid or vitamin C has antioxidant and anti-inflammatory properties that may impact markers of inflammation like C-reactive protein (CRP). However, studies specifically on vitamin C and high-sensitivity CRP (hs-CRP) have been scarce.

Methods: We conducted a cross-sectional analysis of the National Health and Nutrition Examination Survey 2017-2018 dataset including 5,380 U.S. adults aged ≥20 years. Multiple regression models examined the relationship between plasma vitamin C and serum hs-CRP while adjusting for potential confounders. Stratified analyses and curve fitting assessed effect modification and nonlinearity.

Results: An inverse association was found between plasma vitamin C and serum hs-CRP overall (β = -0.025, 95% CI: -0.033 to -0.017, p < 0.00001) and in subgroups except for the "other Hispanic" subgroup in model II (β = -0.009, 95% CI: (-0.040, 0.023), p = 0.5885). The relationship was nonlinear, with the greatest hs-CRP reduction observed up to a plasma vitamin C level of 53.1 μmol/L.

Conclusion: The results showed a non-linear negative correlation between vitamin C levels and hs-CRP in adults. These results suggest vitamin C intake may reduce inflammation and cardiovascular risk, but only up to 53.1 μmol/L plasma vitamin C.

Keywords: NHANES; ascorbic acid; high-sensitivity C-reactive protein; inflammation; vitamin C.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by Changsha Natural Science Foundation (kq2208445), Changsha Central Hospital (YNKY202306).