The OR of anxiety disorders per 1 SD unit increment of serum iron, log-transformed ferritin and transferrin saturation were 0.922 (95% confidence interval (CI) 0.862–0.986; p = 0.018; power = 59.8%), 0.873 (95% CI 0.790–0.964; p = 0.008; power = 74.2%) and 0.917 (95% CI 0.867–0.969; p = 0.002; power = 75.5%), respectively (Fig 2, Table 1). Here, TF is linked to anxiety disorder.