## Impaired kidney function Elevated glucose levels cause the kidneys to work in emergency mode as the body tries to get rid of excess sugar through the urine. If the kidneys are not functioning properly, they do not produce enough of the hormone erythropoietin, on which the synthesis of red blood cells depends. As a result, the level of red blood cells drops and anemia begins. ## Nervous system malfunction Diabetes leads to frequent spikes in blood sugar levels from normal to very high. This disrupts the supply of nutrients to the nerves and can cause neuropathy to develop. In diabetic neuropathy, the kidneys don't get the signal to synthesize erythropoietin. ## Cardiac dysfunction Diabetics are at increased risk of developing heart failure. Deterioration of heart function leads ===to impaired kidney function and nutrient deficiencies, both of which provoke the development of anemia. > Approximately 20 % of people with heart failure also have anemia. ## Nutritional deficiencies Diabetics have to limit themselves to certain foods and often experience nutritional deficiencies as a result. A lack of vital elements, such as iron, vitamin B6, vitamin B12, and folic acid can lead to anemia. ## Celiac disease About 1 in 20 diabetics suffers from celiac disease, which is gluten intolerance. Gluten is a protein found in barley, wheat, and rye. With celiac disease, the body does not get the necessary proteins, fats, carbohydrates, vitamins, and minerals in full, which also causes a deficiency of useful substances. ## Antidiabetic drugs Metformin is widely used to treat type 2 diabetes. This medication provokes a violation of the absorption of vitamin B12, the deficiency of which leads to anemia. Another class of antidiabetic drugs, thiazolidinediones, can also cause mild anemia by slightly lowering hemoglobin and hematocrit levels. > Studies have shown that long-term use (12-15 years) of metformin causes vitamin B12 deficiency in 30 % of people.