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Serum T4

Research analysis led by Kamal Patel.
All content reviewed by the Examine.com Team. Published: Jun 28, 2017
Last Updated:

Summary of Serum T4

Primary Information, Benefits, Effects, and Important Facts

Scientific Information on Serum T4

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Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect serum t4
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
grade-b Minor Moderate See all 5 studies
Supplemental iodine above 500µg appears to be capable of suppressing T4 to a small degree whereas lower doses are not associated with such an effect.
grade-b - High See all 5 studies
Although one study noted a decrease with 600 IU, future studies in similar persons with multiple doses have failed to replicate these observations.
grade-c Minor Very High See 2 studies
The decline in T4 hormone levels during prolonged exercise is abolished with supplementation of zin

All comparative evidence is now gathered in our ​A-to-Z Supplement Reference.

The evidence for each separate supplement is still freely available ​here.

grade-c  
grade-d  
grade-d