The Claim

Selenium supplementation in patients with documented selenium deficiency and elevated FT4/FT3 ratio causes significant reductions in serum FT4 and FT4/FT3 ratio and increases in serum FT3, indicating restoration of peripheral thyroid hormone conversion.

Source: Thyroid function in patients with selenium deficiency exhibits high free T4 to T3 ratio

What the research says

Supports is higher

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

Supports
46score
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.

How it works
1 study reviewed
In plain English

In people with low selenium levels and an abnormal ratio of thyroid hormones FT4 to FT3, taking selenium supplements lowers FT4 and the FT4/FT3 ratio while raising FT3 levels.

See the scientific wording

Selenium supplementation in patients with documented selenium deficiency and elevated FT4/FT3 ratio leads to significant reductions in FT4 and FT4/FT3 ratio and increases in FT3, suggesting restoration of peripheral thyroid hormone conversion, though the clinical significance of these changes remains unproven.

Why this might work

When selenium levels are low, the enzymes that convert the inactive thyroid hormone T4 into the active form T3 stop working properly. This causes T4 to build up and T3 to drop, raising the ratio of T4 to T3. When selenium is restored, these enzymes restart, converting more T4 into T3, which lowers the T4-to-T3 ratio and increases active thyroid hormone levels.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Thyroid function in patients with selenium deficiency exhibits high free T4 to T3 ratio

    When people with low selenium levels and abnormal thyroid hormone ratios took selenium supplements, their body started converting the inactive thyroid hormone (T4) into the active one (T3) better, fixing the imbalance. This suggests selenium helps the thyroid work properly.

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

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