Zinc is distributed in trace amounts among the cells in your body, making it difficult to detect zinc deficiency through a simple blood test.
If your doctor suspects a zinc deficiency, they will need to test your blood plasma for an accurate reading. Other tests for zinc deficiency include a urine test and an analysis of a strand of your hair to measure the zinc content.
Sometimes zinc deficiency is a symptom of another condition. For example, some conditions may cause zinc to be processed in your body but not absorbed well. Zinc deficiency can also lead to copper deficiency. Your doctor will be aware of these possibilities. They may do additional testing to get to the root of your deficiency.
A zinc deficiency can be diagnosed using a blood test, urine test, or hair analysis. As some conditions can lead to a zinc deficiency, your doctor may do additional testing to discover the root cause.