Zinc-Induced Copper Deficiency as a Rare Cause of Neurological Deficit and Anemia

Upper respiratory infections (URIs) are common and carry a large economic burden due to missed work and school. This has prompted an increased interest in over-the-counter zinc supplementation to enhance immunity and reduce illness duration. Zinc's antiviral and anti-inflammatory effects have led to its inclusion in popular URI medications and a surge in supplement sales, particularly among the elderly. However, zinc over-supplementation in this population can lead to hypocupremia, causing various presentations such as anemia, paresthesia, and gait disturbances. Here, we present a case of a 76-year-old female who developed hypocupremia due to zinc supplementation. Her initial presentation involved an unsteady gait, and severe anemia was detected during the examination. The patient's condition required hospital admission, and subsequent investigations confirmed severe pancytopenia and low blood copper levels. Discontinuation of zinc supplementation and oral copper gluconate administration led to a full recovery of her anemia and cell count; however, her neurological deficits remain. This case highlights the importance of counseling patients on the potential adverse effects of zinc supplementation and brings to light a potentially overlooked diagnosis, particularly in the elderly population.