The Claim

In adults with autoimmune hypothyroidism on levothyroxine therapy, daily selenium supplementation at 200 μg for 12 months reduces thyroid peroxidase antibody levels by approximately 19% compared to placebo, without altering thyroid hormone dosage or the free triiodothyronine–free thyroxine ratio.

Source: Selenium supplementation and placebo are equally effective in improving quality of life in patients with hypothyroidism

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
79score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

In people with autoimmune hypothyroidism taking levothyroxine, taking 200 micrograms of selenium daily for a year may lower levels of thyroid peroxidase antibodies by about 19% compared to a placebo, but it does not change the required dose of thyroid hormone or the balance between free triiodothyronine and free thyroxine.

See the scientific wording

In adults with autoimmune hypothyroidism on levothyroxine, daily selenium supplementation (200 μg) for 12 months reduces thyroid peroxidase antibody levels by approximately 19% compared to placebo, but this reduction does not translate to changes in thyroid hormone dosage or the free triiodothyronine–free thyroxine ratio.

What the research says

1 study
  1. Study: Selenium supplementation and placebo are equally effective in improving quality of life in patients with hypothyroidism

    Taking selenium pills for a year lowered a specific antibody in the blood of people with thyroid disease, just like the claim said—but it didn’t change their medication needs or hormone balance.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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