Beef spleen has long been known as a natural food source of iron and now you can easily access this important organ in the convenience of gelatin capsules. Why heme iron is so important ... Heme iron, primarily found in animal sources, is more easily absorbed by the body because it is chemically bound to hemoglobin. In contrast, non-heme iron, derived from plant-based sources and fortified foods, is less efficiently absorbed by the body. Iron is an important mineral and is linked to: Increased Energy Normal Immune Function Normal Blood Formation Reduce tiredness and fatigue