Plasma circulating vitamin C levels and risk of multiple sclerosis: a two-sample Mendelian randomization analysis

Abstract

Whether vitamin C (VitC) supplementation can decrease multiple sclerosis (MS) risk remains controversial. Using data from large-scale genome-wide association studies, we conducted a two-sample Mendelian randomization (MR) analysis to evaluate the causal relationship between plasma circulating VitC levels and MS comprehensively. MR analysis did not support the causality between genetically determined per 1 standard deviation increase (around 20 mmol/L) in circulating VitC levels and MS risk (OR 0.88, 95%CI 0.65-1.18, P = 0.3822), supported by complementary sensitivity analyses, including the weighted median, MR-Egger, and MR Pleiotropy Residual Sum and Outlier test methods.

Keywords: Causality; Mendelian randomization; Multiple sclerosis; Vitamin C.