Influence of iodine on the reference interval of TSH and the optimal interval of TSH: results of a follow‐up study in areas with different iodine intakes

Abstract

Iodine nutrition is an important factor associated with TSH concentration even in the rigorously selected reference population. Baseline TSH of 1.0-1.9 mIU/l is an optimal interval with the lowest incidence of abnormal TSH in 5 years.