Effect of Selenium Supplementation on Thyroid Function in UK Pregnant Women: a Randomised, Controlled Pilot Trial

[...]the combination of Se dose and treatment time did not achieve nutritional Se sufficiency, as measured by plasma SEPP1(3). TSH increased throughout pregnancy in both groups of TPOAb-ve women (Fig. 2) and decreased in the TPOAb+ve women, with an almost three-fold greater decrease in the Se treatment group than in the placebo group though the difference did not reach significance, probably because of the small number of subjects (Fig. 3). There was a correlation between plasma SEPP1 and TSH at 35wks in the placebo group (r=0.206, p=0.031) and with FT4 at 35 wks in the Se group (r=0.251, p=0.01) suggesting that Se may regulate thyroid function differently depending on Se status.