To measure the amount of zinc in the blood (serum/plasma) in order to identify/diagnose deficiency or to monitor response to supplementation
Zinc
When you have symptoms that may suggest zinc deficiency e.g hair loss, poor wound healing
A blood sample taken from a vein in your arm or rarely a 24 hour urine sample
No test preparation is needed (although fasting results are preferred as zinc concentrations can decrease after meals)
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How is it used?
Zinc testing is used to investigate for zinc deficiency. It is also useful for monitoring a person who is being nutritionally supplemented to ensure adequate concentrations are achieved.
Zinc can be tested along with other trace elements (e.g iron, copper & selenium) to identify deficiencies where a person may benefit from supplementation.
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When is it requested?
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What does the test result mean?
Zinc decreases in response to infections so a low result may not necessarily mean a person is zinc deficient. Results should be interpreted with clinical symptoms and clinical history.
Since zinc is transported mainly bound to albumin it can be useful to interpret zinc results alongside albumin concentration . For example a low zinc concentration with a normal albumin can suggest zinc deficiency, whereas a low zinc with a low albumin concentration can suggest an acute phase response to infection and not necessarily zinc deficiency.
High results are rarely seen as excess zinc can be excreted in the urine/faeces. Excessive supplementation of zinc can be toxic to the kidneys. Symptoms of zinc toxicity include nausea, vomiting, lethargy and drowsiness.
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Is there anything else I should know?
Medications such as steroids & oral contraceptives can reduce circulating concentrations of zinc. Pregnancy is associated with low zinc concentrations due to increased circulating hormones in the body.
Medications such as antibiotics and iron may compete with zinc for intestinal absorption if taken together orally.
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Should everyone’s zinc concentrations be measured to check for deficiency?
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When is it recommended to measure urine zinc concentrations?
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Should I be taking zinc supplements?