This handbook provides an overview of the latest science of the influence of nutrition on blood cells and blood diseases. Blood diseases include a broad range of nutritional deficiencies, leukemias and genetic mutations, associated with an increased risk of infections. Reduced red blood cell production can lead to nutritional diseases and anemias, requiring iron supplementation. Patients with anemia feel sick, fatigued and have nausea affecting food intake, worsening their condition. Changes in serum and blood cells affect coagulation, as well as the immune cells’ production of cytokines and immunoglobulin. The blood cells interactions affect all major organ systems. Nutrition and food plays a key role in the health of blood cells and their functions. Vitamins and minerals, such as vitamin E, C and iron, affect the production of blood cells and their proteins, including hemoglobin. In addition, other nutrients, like glutamine, L-carnitine and the amino-acid taurine, play a crucial role in the production of blood cells and blood/related diseases. This book discusses nutritional therapies concerning stem cell transplantation, iron deficiency, cardiovacular diseases, sickle cell anemia and sepsis patients, among others. Nutritional therapy and management in leukemia is given a major focus.The key goal of this handbook is to review some of the nutritional approaches for efficacy in treatment of blood diseases, reduction of their clinical complications and the improvement of the quality of life of these patients.