Zinc is an important trace mineral responsible for enzyme production and proper cellular function. Unlike many other dietary trace minerals, many people are deficient in zinc, producing digestive problems and a wide range of diseases. Like most other minerals, it is also possible to overdose on zinc, producing toxic results. A zinc plasma test can help detect these problems and allows patients to change their diets and lifestyles before zinc imbalances have serious health effects.

Doctors are most likely to prescribe a zinc plasma test for people who show signs of hair loss, acne, poor senses of sight, taste and smell or memory loss. Excessively low levels of zinc in the bloodstream can also cause a lack of desire for food that can lead to severe weight loss. These problems may be caused by a lack of zinc in the diet or by diseases that keep the body from absorbing this mineral, including liver and kidney disease intestinal disorders and diabetes. Patients who have had bariatric surgery sometimes develop zinc deficiencies.

Zinc serum tests don't require any special preparation and can be performed at any time. Normally, blood zinc levels should be between 0.66 micrograms per milliliter and 1.10 mcg/mL. Levels higher than this are not usually considered alarming unless they are also associated with poisoning symptoms, but people who have zinc levels below 0.6 mcg/mL may need supplementation, dietary changes or treatment for illness.