Interesting ImagesAbnormal FDG Uptake on PET/CT Due to Periosteal Reaction Caused by Hypervitaminosis D in a Pediatric PatientLiu, Jun MD; Wang, Wei MD, PhD; Yang, Jigang MD, PhDAuthor Information From the Department of Nuclear Medicine, Beijing Friendship Hospital of Capital Medical University, Beijing, China. Received for publication June 18, 2020; revision accepted June 22, 2020. Conflicts of interest and sources of funding: none declared. Correspondence to: Jigang Yang, MD, PhD, Department of Nuclear Medicine, Beijing Friendship Hospital of Capital Medical University, Beijing, China. E-mail: email@example.com. Clinical Nuclear Medicine: October 2020 - Volume 45 - Issue 10 - p 781-783 doi: 10.1097/RLU.0000000000003230 Buy Metrics Abstract A 7-year-old boy presented with diffuse bone pain. FDG PET/CT was performed to find the possible underlying malignant cause of hypercalcemia. The images demonstrated multiple foci of abnormal FDG activity at the sites of periosteal reaction. In addition, calcium deposit was noted in the basal ganglia, stomach, and the colon. History taking revealed that the patient had routinely taken an over-the-counter “supplement” that contains a high dose of vitamin D. One week after calcitonin therapy and stopping the supplement, the patient became symptom free. This case suggests that hypervitaminosis D might cause hypermetabolic periosteal reaction on FDG PET/CT imaging. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.