Optimal and Safe Upper Limits of Iodine Intake for Early Pregnancy in Iodine-Sufficient Regions: A Cross-Sectional Study of 7190 Pregnant Women in China

Abstract

The upper limit of iodine intake during early pregnancy in an iodine-sufficient region should not exceed UIC 250 μg/L, because this is associated with a significantly high risk of subclinical hypothyroidism, and a UIC of 500 μg/L should not be exceeded, as it is associated with a significantly high risk of isolated hypothyroxinemia.