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 .
Concurrent micronutrient deficiencies are prevalent in nonpregnant rural and tribal women from central India.
OBJECTIVE The existence of concurrent micronutrient deficiencies in Indian women of reproductive age has received little attention . This study aim ed to comprehensively assess the micronutrient status of nonpregnant rural and tribal women 18 - 30 y from central India . METHODS Participants ( n = 109 ) were r and omly selected using a stratified ( rural-tribal ) proportionate-to- population size cluster sampling method from 12 subcenters in Ramtek block , Nagpur . Sociodemographic , anthropometric , dietary , and biochemical data , including blood and urine sample s , were obtained . RESULTS Tribal and rural women had similar sociodemographic characteristics and anthropometric status ; 63 % of women had a body mass index < 18.5 kg/m(2 ) . The median urinary iodine concentration was 215 μg/L ( IQR : 127 , 319 ) . The mean ( SD ) concentration of hemoglobin , serum zinc , retinol , and folate was 112 ( 13 ) g/L , 10.8 ( 1.6 ) μmol/L , 1.2 ( 0.3 ) μmol/L , 18.4 ( 8.4 ) nmol/L , respectively , with a geometric mean serum vitamin B(12 ) concentration of 186 pmol/L. The percentage of women with low values for hemoglobin ( < 120 g/L ) , serum zinc ( < 10.7 μmol/L ) , vitamin B(12 ) ( < 148 pmol/L ) , retinol ( < 0.7 μmol/L ) , and folate ( < 6.8 nmol/L ) was 66 % , 52 % , 34 % , 4 % , and 2 % , respectively . Tribal women had a higher prevalence of zinc deficiency ( 58 % versus 39 % , P = 0.054 ) and concurrent deficiency of any two micronutrients ( 46 % versus 26 % ; P = 0.034 ) , including zinc and anemia ( 38 % versus 21 % , P = 0.024 ) . CONCLUSION Zinc , vitamin B(12 ) , and iron constitute the principal micronutrient deficiencies in these women . Existing supplementation programs should be extended to include 18- to 30-y-old nonpregnant women as the majority of childbearing occurs within this timeframe
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 .