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 .
Association of selenium with thyroid volume and echostructure in 35- to 60-year-old French adults.
OBJECTIVE To investigate the relationship between selenium status , thyroid Volume and gl and echostructure . DESIGN Cross-sectional . METHODS In 792 men ( 45 - 60 Years ) and 1108 women ( 35 - 60 Years ) from the SU.VI.MAX study , thyroid Volume and gl and echostructure were determined ultrasonographically . At baseline , thyrotropin , free thyroxine , selenium , zinc , alpha-tocopherol , beta-carotene , retinol , urinary iodine and thiocyanate concentrations were measured . Alcohol consumption , smoking , and menopausal status were assessed by a question naire . A stepwise linear and a logistic regression model were used , adjusting for antioxidant vitamins , trace elements status and age . RESULTS In women , there was an inverse association between selenium status and thyroid Volume ( P=0.003 ) . A protective effect of selenium against goiter ( odds ratio (OR)=0.07 , 95 % confidence interval (CI)=0.008 - 0.6 ) and thyroid tIssue damage ( OR=0.2 , 95 % CI=0.06 - 0.7 ) was observed . There was no evidence of an association between menopausal status and other antioxidant elements , thyroid Volume or thyroid hypoechogenicity . Smoking , but not alcohol consumption , was associated with an increased risk of thyroid enlargement in women ( OR=3.94 , 95 % CI=1.64 - 9.48 ) . No association between thyroid Volume , thyroid structure or selenium was found in men . CONCLUSION Our findings suggest that selenium may protect against goiter . Selenium was related to thyroid echostructure , suggesting it may also protect against autoimmune thyroid disease
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 .