Which statement about zinc status measurement is true?

Which statement about zinc status measurement is true?

• A. Serum zinc is not a reliable indicator
• B. Serum zinc is a reliable indicator
• C. Serum zinc is the only needed test
• D. Serum zinc is reliable in SIRS

Answer: (A)

Zinc status cannot be judged reliably from a single serum zinc measurement. Only a tiny portion of total body zinc circulates in the blood, and serum zinc is highly variable due to factors like time of day, meals, hydration, and recent physical stress. More importantly, inflammation and acute illnesses trigger zinc redistribution from the blood into tissues such as the liver, a response known as the acute-phase reaction. In states like SIRS, this redistribution can lower serum zinc even when body zinc stores are adequate, or mask true deficiency. Because of these fluctuations, serum zinc has limited sensitivity and specificity for diagnosing zinc status, so it should not be used as the sole indicator. A comprehensive assessment combines dietary intake, clinical signs, growth or wound-healing indicators, functional markers when available, and consideration of inflammatory status and, if needed, response to zinc supplementation.

Zinc status cannot be judged reliably from a single serum zinc measurement. Only a tiny portion of total body zinc circulates in the blood, and serum zinc is highly variable due to factors like time of day, meals, hydration, and recent physical stress. More importantly, inflammation and acute illnesses trigger zinc redistribution from the blood into tissues such as the liver, a response known as the acute-phase reaction. In states like SIRS, this redistribution can lower serum zinc even when body zinc stores are adequate, or mask true deficiency. Because of these fluctuations, serum zinc has limited sensitivity and specificity for diagnosing zinc status, so it should not be used as the sole indicator. A comprehensive assessment combines dietary intake, clinical signs, growth or wound-healing indicators, functional markers when available, and consideration of inflammatory status and, if needed, response to zinc supplementation.