Duck blood is a common food and does not belong to the category of drugs, so it does not have therapeutic efficacy and effect, but can be used to supplement protein and other nutrients. Duck blood is rich in iron, protein, vitamin A, calcium and other nutrients. 100 grams of duck blood contains 150 calories, of which 26.9 grams of protein, 1.9 grams of fat, 6.2 grams of carbohydrates, 24 milligrams of calcium, 36 milligrams of cholesterol. Among them, iron helps to generate hemoglobin and maintain the function of red blood cells; protein helps to constitute and repair human tissues and helps the growth of muscles and bones; vitamin A helps to maintain the function of dark vision; calcium helps to maintain the health of human bones and teeth, and also helps to maintain the function of neuromuscular and so on. Note that it is not advisable to consume large quantities of duck blood, not through the simple consumption of duck blood to supplement the above nutrients, frequent diarrhea is recommended to eat less. Duck blood is a common food, not a medicine, and therefore has no efficacy or effect. If you want to treat a disease, it is recommended to ask your doctor for medication.