Author Affiliations: Department of Neurosciences and Mental Health, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada (Dr Hanwell), and Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada (Dr Kimball).
Marcus et al1 described a patient with progressive multiple sclerosis presenting with symptomatic hypercalcemia. As emphasized by the title of their article, the authors concluded that hypercalcemia was at least partly due to vitamin D toxicity. We disagree. Vitamin D did not play a role in this case of hypercalcemia. Rather, the patient's clinical and biochemical presentation, and especially the successful resolution simply by rehydrating with saline, is entirely consistent with a dehydrated patient who consumed excessive calcium.
Hanwell HE, Kimball SM. Acute Hypercalcemia Following Excessive Calcium Supplementation in a Dehydrated Patient With Progressive Multiple Sclerosis: Vitamin D Supplementation Is a Red Herring. Arch Neurol. 2012;69(6):793–794. doi:10.1001/archneurol.2012.200