Although observational evidence suggests that concentrations of selenium , zinc , and iron are positively associated with iodine status , data from r and omized controlled trials fail to confirm this relationship .
Context The metabolism of thyroid hormones , which are essential for normal development , involves many proteins and enzymes .
It requires iodine as a key component but is also influenced by several other micronutrients , including selenium , zinc , iron , and vitamin A. Objective This systematic review was design ed to investigate the effect of micronutrient status and supplementation on  iodine status and thyroid hormone concentrations .
The Relationship Between Iron Status and Thyroid Hormones in Adolescents Living in an Iodine Deficient Area
BACKGROUND Iron may be only one of many nutritional factors that influence thyroid hormone metabolism in iodine-deficient areas . OBJECTIVE To evaluate the effect of iron status on thyroid hormone profile in adolescents living in a mild iodine-deficient area in Turkey . SUBJECTS Three hundred and thirty school-aged children with mean age 14 years were examined . METHODS Free triiodothyronine , free tetraiodothyronine and thyrotropin levels were analyzed by chemiluminescent enzyme immunoassay .  Hemoglobin and mean corpuscular volume were measured with a Hemocounter . Iron and total iron binding capacity concentration were determined by colorimetric photometric methods . Ferritin level was determined by immunoturbidimetry . RESULTS Thyroid hormone levels of the children with anemia were not significantly different compared to children without anemia . No significant correlation was found between thyroid hormones and iron status . CONCLUSION The thyroid hormone profile was not significantly affected in this area . This survey showed no correlation between iron status and thyroid hormone levels
Although observational evidence suggests that concentrations of selenium , zinc , and iron are positively associated with iodine status , data from r and omized controlled trials fail to confirm this relationship .
Context The metabolism of thyroid hormones , which are essential for normal development , involves many proteins and enzymes .
It requires iodine as a key component but is also influenced by several other micronutrients , including selenium , zinc , iron , and vitamin A. Objective This systematic review was design ed to investigate the effect of micronutrient status and supplementation on  iodine status and thyroid hormone concentrations .