James “Jim” Dennis Cook, age 84, of Olathe, Kansas, died under the loving care of caregivers at Brookdale College Square after a courageous battle with Alzheimer’s on November 18, 2020. Jim was born on July 7, 1936, in Tillsonburg, Ontario, Canada to Rev. Milton and Isobel (nee Blair) Cook. Jim graduated from St. Thomas Collegiate Institute in 1954 where he met Carolyn Farrow, his high school steady and wife of 53 years. Jim attended Medical school at Queens University in Kingston, Ontario and graduated as a Medical Doctor in 1960. Jim's son, Gregory, and daughter Cheryl, were born in Kingston as Jim finished medical school and started his illustrious career as a researcher, teacher, and clinician, and followed his medical degree with a Master’s in Medicine and his Junior residency in Internal Medicine in Kingston. In 1964 Jim and his family immigrated to the US where Jim did his Senior Residency in Internal Medicine at Boston City Hospital, Boston MA in 1964-65. Jim’s daughter Dianne was born in Boston in 1965. In 1965 he moved his family to Seattle, WA to pursue a fellowship in Hematology at the University of Washington, where their son Paul was born in 1966. After serving at UW as an assistant professor, he moved his family to Lenexa, Kansas in 1975 where he became the Head of Department of Hematology at the University of Kansas Medical Center and retired as Emeritus Professor of Medicine. Jim and his wife Carolyn became US citizens in 1976. Jim was a world-renowned expert in the area of Iron Metabolism, having published 250 publications during his career. He served as the director of the WHO Center for the Control of Nutritional Anemia and chaired and participated in many international committees. Jim enjoyed the outdoors, traveling, music, and games and puzzles, but seemed to excel in every endeavor he pursued. He was greatly loved and will be greatly missed. He is survived by his brothers Bruce and Robert (Sally) Cook; children Rev. Dr. Gregory (Nancy) Cook of Fort Worth, TX., Cheryl (Scott) Cook Sperry of Olathe, KS, Dianne (Wayne) Cook Walker of Lenexa, KS and Paul (Robin) Cook of Overland Park, KS; grandchildren Ashley (Matt) Sherwood, Stephanie (Micah) Dettmer, and Anna Cook, Zachary Sperry, Emma, Izzy and Abby Walker, and Bailey Cook; great-grandchildren Greg and Bonnie Dettmer, as well as many nephews, nieces, admiring friends, co-workers and neighbors. Jim was preceded in death by his parents, his beloved wife, Carolyn “CJ”; his grandson Jack Cook; and his daughter-in-law Robin Cook and sister-in-law, Grace Cook. A private internment will be held at Olathe Memorial Cemetery, Olathe, Kansas. In lieu of flowers, contributions may be sent to Overland Park Arboretum & Botanical Gardens. Condolences may be offered at Porter Funeral Home (www.porterfuneralhome.com), Lenexa, KS.