The Zinc Serum test measures the level of this vital mineral in your blood. Zinc is an essential nutrient for a healthy immune system, proper wound healing, and your sense of taste and smell. A deficiency can lead to frequent illnesses, slow-healing wounds, or other unexplained symptoms. This test requires a simple blood draw. Feeling run-down? This simple test provides a clear look at a key pillar of your body's defense system, helping you get back to 100%.