Several years ago, two of us published a full-length textbook entitled Nutrition and Immunology: Principles and Practice. The book was aca demically successful and well received by our peers. Our colleagues commented that while the book was eminently suitable for a library, there was still an intellectual need for a more concise volume on nutrition and immunology for health care providers and scientists working at the inter face of delivering therapeutic and/or preventive health care. We agreed and decided that a book focused on issues relevant to laboratory workers and to developing countries would be valuable. We invited well-known experts in their fields to contribute a chapter each and asked that they err on the short rather than the long side and update cited review articles rather than original papers wherever possible. The Handbook of Nutrition and Immunity is the culmination of that process. Our intention is that the book will grow over time and new editions will fill identified voids that meet the changing needs of health care providers and scientists interested in the practical aspects related to evaluating nutrition and immunology in the field. The Handbook of Nutrition and Immunity is for those people working in both adult and child nutrition throughout the world. It is also of relevance to those in the pharmaceutical and the food industry who are interested in developing ways to evaluate both the efficacy and effective ness of their products.