Related Experiment Video
Updated: May 11, 2025

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
Published on: June 21, 2018
Association Between Circulating Vitamin C Concentrations and Risk of Diabetes Mellitus: Dual Evidence From NHANES
Zhitong Li1, Jinchang Liu1, Xingyu Li2
1Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, China; The Key Laboratory of Endocrine and Metabolic Diseases of Shanxi Province, Shanxi Bethune Hospital, Taiyuan, China.
Objectives:
A relationship between vitamin C and diabetes risk has been proposed. Given the limited evidence specifically for type 1 diabetes (T1DM), we examined the association between vitamin C and T1DM using standard epidemiologic and Mendelian randomization (MR) approaches.
Methods:
Data from a cross-sectional study using the National Health and Nutrition Examination Survey (NHANES; n=15,080 adults) were analyzed using logistic regression to estimate the association between vitamin C and diabetes risk, adjusting for demographic and lifestyle factors. Because NHANES does not distinguish T1DM, and the cross-sectional design may be susceptible to reverse causation, we performed a 2-sample MR analysis, using single-nucleotide polymorphisms (SNPs) as instrumental variables to evaluate causal links specifically between vitamin C and T1DM. SNPs for vitamin C and T1DM were obtained from large genome-wide association studies.
Results:
NHANES data indicated an inverse relationship between vitamin C and diabetes. Participants in the highest quartile of vitamin C had lower odds of diabetes, with an odds ratio of 0.482 (95% confidence interval [CI] 0.368 to 0.628) compared with those in the lowest quartile. The MR analysis showed no significant association between vitamin C levels and T1DM, with an odds ratio for T1DM per unit (millimoles per litre) increase in vitamin C of 0.852 (95% CI 0.681 to 1.066, p=0.161).
Conclusions:
Elevated circulating vitamin C was inversely associated with diabetes in an NHANES cross-sectional study, but we were unable to confirm a causal relationship using MR.
Related Concept Videos
Diabetes Mellitus: Type 2 and Gestational
Psychoneuroimmunology: Diabetes and Cancer
Cancer Prevention
Some...
Genome-wide Association Studies-GWAS
GWAS does not require the identification of the target gene involved in...
Nature and Nurture
Single Nucleotide Polymorphisms-SNPs

