Ellingsen TS, et al. - In this nested case-control study, researchers investigated if iron deficiency is a risk factor for venous thromboembolism (VTE) and if iron deficiency explains the link between red cell distribution width (RDW) and VTE. They selected patients with VTE and age- and sex-matched controls from the population-based cohort of the Tromsø Study and using logistic regression models, estimated odds ratios (ORs) with 95% confidence intervals (CIs) for VTE by RDW, hepcidin, and ferritin light chain (FtL). They found an increase in the risk of VTE by categories of higher RDW. Furthermore, inclusion of hepcidin and FtL in the multivariable model led to strengthening of the risk of VTE. The hypothesis that iron deficiency explains the association between RDW and VTE was rejected. Data suggested that the risk of VTE might be increased by high body iron levels.