As one of the pharmacy specialist pioneers, Professor Mirtallo was instrumental in leading cost-effective practices in parenteral nutrition and advancing the role of the pharmacist on nutrition support services. His research focused on comparative evaluations of amino acid injection products, the use of fat as a calorie source, PN compatibility and stability, and systems issues in the management of parenteral nutrition. Professor Mirtallo is Past President of the American Society for Parenteral and Enteral Nutrition (ASPEN). He is involved with the ASPEN Public Policy Committee where he advocates for reimbursement of PEN in the hospital and home, works to improve the safety and efficacy of PN. He served on the Joint Commission task force that created the Nutrition Care Standards. Mirtallo has been actively involved with nutrition support guidelines and co-authored an etiology-based definition of malnutrition which is the basis for an inter-professional malnutrition strategy. He chaired a PN safety summit in 2011 which led to the development of the safety consensus recommendations recently released by ASPEN. Currently, Mirtallo is Professor Emeritus at The Ohio State University, College of Pharmacy, Division of Pharmacy Practice and Administration and Clinical Practice Specialist, The American Society for Parenteral and Enteral Nutrition.