This is a Career Advancement Award to support Dr. Thierry- Palmer's sabbatical visit to Dr. John Suttie's laboratory at the University of Wisconsin. The goal of the project is to identify vitamin K-dependent proteins and determine their function, with special attention to their possible role in calcium ion concentration homeostasis in mitochondria. Dr. Thierry-Palmer has an established record of productivity in the area of vitamin D metabolism. This sabbatical visit will permit her to return to her earlier interest in vitamin K, and develop a new line of research which is anticipated to significantly enhance her career.