It has been reported and confirmed that Marshall Islanders have protein-bound iodine (PBI) values about 2 μg/deciliter higher than Americans. In the present study, approximately 2,500 PBI values obtained from various populations of the Western Pacific were grouped on ethnic and geographic bases to see if other populations showed this elevation. Appropriate statistical methods did not show significant variation in PBI levels in groups taking high fish diets, on a racial basis, or in subjects exposed to irradiation.
Burdick CO, Brown RK. Protein-Bound Iodine Variations. Arch Intern Med. 1968;121(1):54-56. doi:10.1001/archinte.1968.03640010056008