In a malnourished child suspected of having marginal zinc deficiency, which serum enzyme serves as a practical biochemical marker of zinc status?

• A Alanine aminotransferase, which rises with zinc depletion
• B Alkaline phosphatase, which falls with zinc depletion ✓
• C Creatine kinase, which falls with zinc depletion
• D Amylase, which rises with zinc depletion

Explanation

Alkaline phosphatase is a zinc metalloenzyme, and its activity in serum falls measurably with zinc depletion, rising again on zinc repletion, so it is used as a functional index of zinc status. Plasma zinc levels themselves fluctuate with meals and albumin concentration and are unreliable alone. ALT reflects hepatocyte injury, creatine kinase muscle injury, and amylase pancreatic or salivary pathology; none of these is a zinc-dependent marker used for nutritional assessment.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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