Fifty-four participants with IDNA (ferritin < 100 μg/L or transferrin saturation < 20% and haemoglobin 110–150 g/L) and CKD stages G3b–G5 were randomised 1:1 to receive either 1000 mg FDI (n = 26) or placebo (n = 28). Here, TF is linked to chronic kidney disease.