D.A. Saia is an author known primarily for writing educational material within the medical field, particularly in the area of radiography. She is the author of "Radiography PREP Program Review and Exam Preparation," which serves as a study guide for students preparing for certification exams in the field of radiologic technology, including the American Registry of Radiologic Technologists (ARRT) certification exam. Her work is appreciated for its comprehensive content that helps students understand and retain the key concepts needed for success in their professional examinations and careers.