Daily dietary vitamin C intake and chronic kidney disease prevalence in older adults: NHANES 1999–2018 and nomogram development
Year: 2026
Type: article
Study design: Observational Study
Abstract: To investigate the association between daily dietary vitamin C intake and chronic kidney disease (CKD) prevalence among older adults and to develop a predictive nomogram model using NHANES 1999–2018 data. Based on National Health and Nutrition Examination Survey 1999–2018, participants aged ≥60 years were included. Weighted multivariable logistic regression was used to assess the association between daily dietary vitamin C intake (excluding supplements) and CKD prevalence, with restricted cubic spline (RCS), subgroup, and sensitivity analyses performed to verify robustness. The sample was randomly divided into training and validation sets (7:3 ratio) to identify independent predictors and construct a nomogram model. Model performance was evaluated using the area under the curve (AUC), calibration plots, and decision curve analysis (DCA). A total of 6540 participants aged ≥60 years were included. Daily dietary vitamin C intake was inversely associated with CKD prevalence after full adjustment (OR per 1 mg increase = 0.998, 95% CI: 0.997–0.999, P = 0.004). Compared with the lowest quartile, the highest quartile showed a significantly lower CKD prevalence (OR = 0.778, 95% CI: 0.610–0.992). Restricted cubic spline analysis indicated a linear relationship. The nomogram constructed based on independent predictors showed good discrimination (AUC = 0.737 in the training set and 0.715 in the validation set), good calibration, and favorable clinical utility within the threshold probability range of 0.09–0.81. In this cross-sectional study of older adults, higher dietary vitamin C intake was inversely associated with CKD prevalence; the nomogram performed well and may aid risk assessment. • Higher dietary vitamin C intake is inversely associated with CKD prevalence in older adults. • A nomogram was developed for CKD risk prediction, showing good discrimination and calibration. • Subgroup analyses confirm vitamin C intake's link to CKD across demographics. • Restricted cubic spline analysis reveals a linear relationship between vitamin C intake and CKD. • Sensitivity and subgroup analyses confirm the robustness of the findings and model performance.
Source: Experimental Gerontology
Authors: Limei Zeng, Xiujun Li, Ying Wang
Institution: Chengdu Fifth People's Hospital
Language: English
Subfield: Nephrology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,400
OpenAlex ID: W7134951003