Moen GH, et al. - Given that several observational studies have demonstrated that low serum vitamin B-12 is linked with adverse cardiometabolic outcomes and increased body mass index (BMI), researchers used a 2-sample Mendelian randomization (MR) method to determine if there exists a causal association between vitamin B-12 and indicators of body fat, lipid, and glucose variables, type 2 diabetes (T2D), and cardiovascular disease. They also investigated whether fucosyltransferase 2 (FUT2) has a pleiotropic role. A causal relation between serum concentrations of vitamin B-12 and body weight or the majority of cardiometabolic outcomes investigated was not found in this study. However, a possible causal impact of vitamin B-12 on fasting glucose and homeostatic model assessment of β cell function was seen.