Longitudinal trends in thyroid function in relation to iodine intake: ongoing changes of thyroid function despite adequate current iodine status

Abstract

In this longitudinal study, we found an ongoing decrease in TSH and increase in FT₄ in a previously iodine insufficient population, despite the adequate iodine status at present. This suggests that low iodine intake at young age leads to thyroid autonomy (and a tendency to hyperthyroidism) that persists despite normal iodine intake later in life.