Define Assessment of Selenium Status?

Blood glutathione (GSH) peroxidase activity is directly related to blood selenium up to a level of 1.27 μmoles/L. Beyond this point, the activity of the enzyme plateaus and therefore cannot be used for assessing selenium status. As of now, GSH peroxidase remains a useful index over the assessment of usual dietary intakes but is limited by the peak level reached at 1.27 mmol/L. Plasma selenium level is an index of short term status, as it has been shown to respond to selenium supplementation more rapidly in deficient individuals than whole blood selenium. Hair and nail selenium are not as yet established as valid parameters, although they are being investigated.