AUTHOR=Ding Ning , Zeng Zhao , Luo Ju , Li Keng 

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

JOURNAL=Frontiers in Nutrition

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1290749

DOI=10.3389/fnut.2023.1290749

ISSN=2296-861X

ABSTRACT=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.