Table 3. Effect of Selenium Supplementation on TPO antibodies in Eight Randomized Clinical Trials.

Study	Selenium preparation	Outcome TPO-Ab	On L-T4	No. of patients, placebo/selenium	Baseline Se, µg/L	Baseline TPO-Ab, kU/L
Gartner et al. (2002) [23]	Selenite	Fall	Yes	34/36	69	904
Duntas et al. (2003) [24]	SeMet	Fall	Yes	31/34	75	1,875
Turker et al. (2006) [25]	SeMet	Fall	Yes	40/48	-	803
Karanikas et al. (2008) [26]	Selenite	No change	Yes	18/18	75	524
Nacamulli et al. (2010) [27]	Selenite	No changea	No	30/46	-	172
Eskes et al. (2014) [28]	Selenite	No change	No	30/31	74	1,508
Pilli et al. (2015) [29]	SeMet	No change	No	20/40	82	409
de Farias et al. (2015) [30]	SeMet	Fall	Yes	27/28	37	1,009

TPO-Ab, thyroid peroxidase antibody; Se, selenium; Selenite, sodium selenite; SeMet, selenomethionine.

^aFall at 1 year.