Table_1_The cross-sectional relationship between vitamin C and high-sensitivity C-reactive protein levels: insights from NHANES database.docx

BackgroundAscorbic 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.MethodsWe 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.ResultsAn inverse association was found between plasma vitamin C and serum hs-CRP overall (β = −0.025, 95% CI: −0.033 to −0.017, p ConclusionThe 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.