The best sources of heme iron, which is most easily absorbed, include beef or chicken liver, clams, oysters, mollusks and mussels. Additional sources suggested by WebMD include cooked turkey, chicken, ham, beef and sardines canned in oil. Veal is another iron-rich food recommended for the treatment of anemia.
Fish high in heme iron include salmon, tuna, halibut, haddock and perch. Because heme iron is found in hemoglobin, animal foods such as fish, poultry and red meats contain the highest amounts. The human body absorbs the most iron from heme sources, primarily in the upper part of the small intestine. Plant sources of iron, such as spinach, beans and lentils, provide nonheme iron. This is the iron added to iron-fortified foods, which is absorbed less efficiently than the animal-derived heme iron.
When iron intake is insufficient, there is a decrease in the number of red blood cells that often results in iron-deficiency anemia, the most common type. Low iron levels prevent the body from producing sufficient hemoglobin, the oxygen-carrying substance found in red blood cells. The body’s tissues are then deprived of necessary oxygen, resulting in fatigue, weakness and irritability, the most common symptoms of anemia. As of 2015, approximately 20 percent of women and 3 percent of men lack sufficient iron. Approximately 50 percent of pregnant women are iron deficient.