Effect of Selenium‑Enriched Yeast Supplementation on Serum Thyroid‑Stimulating Hormone and Anti‑Thyroid Peroxidase Antibody Levels in Subclinical Hypothyroidism: Randomized Controlled Trial

In the subclinical hypothyroidism, T4 or T3 levels are normal and thyroid‑stimulating hormone (TSH) is slightly high. Selenium deficiency can lead to thyroid dysfunction. The present study aims to investigate the effect of selenium supplementation on the thyroid hormone and anti‑thyroid peroxidase antibody (anti‑TPO AB) levels.

In this double‑blinded, randomized, placebo‑controlled clinical trial, 42 patients with subclinical hypothyroidism were randomly assigned to receive 200 μg selenium or placebo for 8 weeks. In the both groups, the serum TSH and anti‑TPO antibody levels were measured and assessed before and after the intervention.

After the interventions, the mean serum TSH reduction in the intervention and placebo groups was −10.98 ± 33.31 and −3.20 ± 38.36, respectively, which were not statistically significant. However, the mean serum anti‑TPO Ab concentration increased in the intervention and placebo groups (109.81 ± 51.49% vs. 173.17 ± 96.26%), between which the difference was not statistically significant (P >0.05) despite a slight increase in the mean anti‑TPO level in the intervention group.

The results of the current study indicated that selenium supplementation has no significant effect on serum anti‑TPO Ab and TSH levels in the patients with subclinical hypothyroidism. Studies with larger sample size and with different doses of selenium are needed to reach more precise results.