title: Effects of Zinc and Selenium Supplementation on Thyroid Function in Overweight and Obese Hypothyroid Female Patients: A Randomized Double-Blind Controlled Trial.
abstract: OBJECTIVE
  Zinc (Zn) and selenium (Se) are essential trace elements involved in thyroid hormone metabolism. This study was conducted to investigate the effects of Zn and Se supplementation on thyroid function of overweight or obese female hypothyroid patients in a double-blind, randomized controlled trial.
  
  
  METHODS
  Sixty-eight female hypothyroid patients were randomly allocated to one of the 4 supplementation groups receiving Zn + Se (ZS; 30 mg Zn as zinc-gluconate and 200 μg Se as high-selenium yeast), Zn + placebo (ZP), Se + placebo (SP), or placebo + placebo (PP) for 12 weeks. Serum Zn, Se, free and total triiodothyronine (FT3 and FT4), free and total thyroxine (FT4 and TT4), thyroid-stimulating hormone (TSH), and anthropometric parameters were measured. Dietary intake was recorded using 24-hour food recall. Physical activity questionnaire was completed.
  
  
  RESULTS
  No significant alterations were found in serum Zn or Se concentrations. Mean serum FT3 increased significantly in the ZS and ZP groups (p < 0.05) but this effect was significant in the ZP group compared to those in SP or PP groups (p < 0.05). Mean serum FT4 increased and TSH decreased significantly (p < 0.05) in the ZS group. TT3 and TT4 decreased significantly in the SP group (p < 0.05). Mean FT3:FT4 ratio was augmented significantly in the ZP group (p < 0.05). No significant treatment effects were found for TT3, FT4, TT4, or TSH between groups.
  
  
  CONCLUSIONS
  This study showed some evidence of an effect of Zn alone or in combination with Se on thyroid function of overweight or obese female hypothyroid patients.
authors.affiliation: a Department of Clinical Nutrition, School of Nutritional Sciences & Dietetics, Tehran University of Medical Sciences , Tehran , IRAN.
authors.forename: Salma
authors.initials: S
authors.lastname: Mahmoodianfard
authors.affiliation: c Department of Nutrition, School of Public Health, Iran University of Medical Sciences , Tehran , IRAN.|d Endocrine Research Center (Firouzgar), Institute of Endocrinology and Metabolism (Hemmat Campus), Iran University of Medical Sciences , Tehran , IRAN.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Vafa
authors.affiliation: d Endocrine Research Center (Firouzgar), Institute of Endocrinology and Metabolism (Hemmat Campus), Iran University of Medical Sciences , Tehran , IRAN.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Golgiri
authors.affiliation: b Endocrinology Department, School of Medicine, Tehran University of Medical Sciences , Tehran , IRAN.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Khoshniat
authors.affiliation: e Department of Statistics, School of Management and Medical Information Sciences, Iran University of Medical Sciences , Tehran , IRAN.
authors.forename: Mahmoodreza
authors.initials: M
authors.lastname: Gohari
authors.affiliation: a Department of Clinical Nutrition, School of Nutritional Sciences & Dietetics, Tehran University of Medical Sciences , Tehran , IRAN.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Solati
authors.affiliation: a Department of Clinical Nutrition, School of Nutritional Sciences & Dietetics, Tehran University of Medical Sciences , Tehran , IRAN.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Djalali
mesh_terms: D000328:Adult; D000368:Aged; D019587:Dietary Supplements; D004311:Double-Blind Method; D002149:Energy Intake; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy*; D008875:Middle Aged; D009043:Motor Activity; D015596:Nutrition Assessment; D009765:Obesity / Q000188:drug therapy*; D050177:Overweight / Q000188:drug therapy*; D012643:Selenium / Q000008:administration & dosage* / Q000097:blood; D011795:Surveys and Questionnaires; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism; D013963:Thyroid Hormones / Q000097:blood; D015032:Zinc / Q000008:administration & dosage* / Q000097:blood
chemical_list: D013963:Thyroid Hormones; D012643:Selenium; D015032:Zinc
keywords: selenium; supplementation; thyroid function; zinc