A Mendelian randomization study on the causal relationship between 25-hydroxyvitamin D and attention deficit hyperactivity disorder
Objective To explore the causal relationship between 25-hydroxyvitamin D[25(OH)D]and attention deficit hyperactivity disorder(ADHD).Methods The two-sample Mendelian randomization(TSMR)method was employed.Genetic data from publicly available genome-wide association studies(GWAS)of Europeans from different samples were used.25(OH)D was taken as the exposure,its single nucleotide polymorphism(SNP)as instrumental variables,and ADHD as the outcome variable.Causal inferences were made through inverse variance weighted(IVW)(multiplicative random effects),MR-Egger method,weighted median(WME)and weighted mode(WM).Data analysis and visualization were processed by R software.Results In the forward Mendelian randomization(MR)analysis,124 SNP of 25(OH)D were included.The effect evaluation results of the IVW method showed that the influence of 25(OH)D on ADHD was not statistically significant(P=0.5681).In addition,neither the MR-Egger method(P=0.1788),WME method(P=0.3823),nor the WM(P=0.5538)found that the influence of 25(OH)D on ADHD was statistically significant.The results of the reverse MR analysis showed that there was no causal relationship between ADHD and 25(OH)D(P>0.05).Conclusion No causal relationship between 25(OH)D and ADHD was found.