SGLT2 (sodium-glucose cotransporter 2) inhibitors have been shown to increase hematocrit and hemoglobin, and correct and prevent anemia in patients with heart failure.12–14 Although the increase in hematocrit was originally thought to reflect volume contraction caused by diuresis, it is now thought that SGLT2 inhibitors also stimulate erythropoiesis.15–19 Erythropoiesis uses iron and may be restricted by existing iron deficiency. This evidence concerns the gene SLC5A2 and nutritional disorder.