Determine some assessment measures of Zinc?
- Measurement of zinc in plasma: This is the most common method. Fasting concentrations of less than 70 μg/litre suggests deficiency. However, fasting plasma zinc level decreases only when dietary intake is so low that homeostasis cannot be maintained. It should be noted that while making interpretations, plasma zinc levels can also be affected by stress infections and administration of oral contraceptives.
- Measurement of zinc in RBCs and neutrophils: This method is not common.
- Metallothionein concentration: Serum metallothionein concentrations are less sensitive to zinc deficiency than levels in RBCs.
- Urinary zinc levels: Excretion of zinc in urine decreases with severe zinc deficiency. It has been suggested as an alternate method of assessing oral zinc absorption using oral dose of 10-50 mg elemental zinc.
- Hair zinc level: Low zinc may be associated with chronic low intakes of dietary zinc. However, it is important that contamination of hair with shampoo, hair colour should be eliminated.
- Measurement of activity of zinc-dependent enzymes: In zinc deficiency, the activity of alkaline phosphatase declines faster than that of carbonic anhydrase.