Concentration of serum protein-bound iodine in normal men.

During recent years the determination of the protein-bound iodine (PBI) in the serum or plasma has been used with increasing frequency as a diagnostic aid. Various limits have been suggested for the serum PBI concentration in euthyroidism. The range most frequently recorded in the literature is from 4 to 8 gamma per cent of PBI. These values are not fiducial expressions of full statistical analyses of adequate numbers of persons; they are based on observations made by several groups of workers on limited numbers of persons judged to be euthyroid but otherwise not fully characterized (Table I). The present paper