Influence of iodine on the reference interval of TSH and the optimal interval of TSH

“The aim of the present study was to evaluate whether the status of iodine nutrition influences the TSH concentration in a selected Chinese reference population according to the criteria proposed by National Academy of Clinical Biochemistry (NACB) and regular thyroid ultrasonography, to establish a new reference interval of TSH based on the wide variation of iodine nutrition in populations, and to identify an optimal interval of TSH by following up the cohort with normal TSH concentrations at baseline”

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2265.2007.03150.x/abstract