The Claim
Supplementing with 100–300 micrograms of selenium per day for six months has no effect on the conversion of thyroxine (T4) to triiodothyronine (T3) in euthyroid adults aged 60–74 years with baseline plasma selenium levels around 91 micrograms per liter, despite increasing plasma selenium concentrations.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Taking 100–300 micrograms of selenium daily for six months does not increase the conversion of thyroxine to triiodothyronine in healthy adults aged 60–74 with normal selenium levels, even though selenium levels in the blood rise.
See the scientific wording
Supplementing with 100–300 micrograms of selenium per day for six months does not improve the conversion of thyroxine (T4) to triiodothyronine (T3) in euthyroid adults aged 60–74 years with baseline plasma selenium levels around 91 micrograms per liter, despite significantly raising plasma selenium concentrations, indicating that selenium status in this population is not a limiting factor for thyroid hormone activation.
Selenium is built into enzymes that remove iodine from the inactive thyroid hormone T4 to make the active form T3. When selenium levels are already sufficient, adding more selenium does not increase enzyme activity or T3 production.
What the research says
1 studyTaking selenium pills every day for six months didn't help healthy older adults turn their thyroid hormone into its active form, even though their selenium levels went up. Their bodies were already getting enough selenium, so more didn't help.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.