Zinc in Serum / Plasma is a test used to measure the level of zinc in the body, an essential mineral that plays an important role in supporting immune function, promoting cellular growth, and aiding wound healing. This test is performed to diagnose zinc deficiency, which may lead to health issues such as weakened immunity, hair loss, and growth delays. It is also requested in cases of suspected zinc excess due to overconsumption of zinc supplements, which may cause symptoms such as nausea or digestive disturbances.